The United States and Iran are set to take part in a new round of international negotiations on the Iranian nuclear program. Thursday’s talks follow speeches by President Obama and new Iranian president, Hassan Rouhani, before the U.N. General Assembly, each opening the window to diplomatic engagement. In his comments, President Obama insisted the United States does not seek regime change in Iran and welcomed what he called Rouhani’s popular mandate for a “moderate course.”

President Obama: “We are encouraged that President Rouhani received from the Iranian people a mandate to pursue a more moderate course. And given President Rouhani’s stated commitment to reach an agreement, I am directing John Kerry to pursue this effort with the Iranian government in close cooperation with the European Union, the United Kingdom, France, Germany, Russia and China. The roadblocks may prove to be too great, but I firmly believe the diplomatic path must be tested.”

Hours later, Rouhani echoed Obama’s call for diplomacy. He reiterated Iran has no nuclear ambitions, but affirmed its right to enrich uranium within international norms. Rouhani also blasted what he called “violent” U.S.-led sanctions on Iran, which he compared to those imposed on Iraq after the first Gulf War.

In his U.N. address, President Obama openly embraced an aggressive military doctrine backed by previous administrations on using armed force beyond the international norm of self-defense. Obama told the world the United States is prepared to use its military to defend what he called “our core interests” in the Middle East: U.S. access to oil.

President Obama: “The United States of America is prepared to use all elements of our power, including military force, to secure our core interests in the region. We will confront external aggression against our allies and partners, as we did in the Gulf War. We will ensure the free flow of energy from the region to the world.”

A group of United Nations weapons inspectors has returned to Syria to continue investigating reports of chemical weapons use there. Their probe will include gathering evidence about an attack on the village of Khan al-Assal near the city of Aleppo on March 19 that reportedly killed dozens. Both the government and Syrian rebels have blamed each other for the attack. A previous report by the inspectors confirmed the nerve agent sarin was used in the deadly attack in Ghouta last month.

The Obama administration is ending months of delay with the signing of the first-ever treaty regulating the global arms trade. The pact was approved earlier this year after the White House initially blocked it until after President Obama’s bid for re-election. The treaty will have no impact on domestic gun laws, but will bring new regulations to the sales of conventional arms. Secretary of State John Kerry is expected to add the U.S. signature today at the U.N. General Assembly. But it will still face a tough ratification vote in the Senate, where it will need two-thirds support for approval. The National Rifle Association is expected to continue its vocal campaign for the treaty’s rejection. In a statement, Amnesty International welcomed the U.S. signature as “a milestone towards ending the flow of conventional arms that fuel atrocities and abuse.”

In an address to the U.N. General Assembly on Tuesday, Nigerian President Goodluck Jonathan said the arms governed by the treaty have sustained deadly cross-border rebellions by militant groups. Jonathan said: “For us in Africa, these are the weapons of mass destruction.” An attack last week by the Islamist rebel group Boko Haram on a highway in northeastern Nigeria left at least 142 people dead.

Kenya has begun three days of mourning for at least 67 people killed in the siege of the Westgate Mall in Nairobi. The death count could still rise if more bodies are found in the rubble of the mall’s three floors. On Tuesday, Kenyan President Uhuru Kenyatta declared final victory four days after the attack began. Kenyatta said at least five militant attackers were killed by gunfire and 11 other suspects are in custody. The Somali militant group al-Shabab has claimed responsibility for the attack, calling it retaliation for Kenyan military intervention in Somalia. On Tuesday, attack survivor Aleem Manji made an appeal for people not to conflate the militants’ actions with the teachings of Islam.

Aleem Manji: “This is not Islam. Islam is something else altogether. Islam is peace. Islam is about togetherness, humanity. What I saw there was not Islam. And if you ever, ever think for a minute that those people represent us, they don’t. And they never will. And please don’t let them win by thinking it.”

The death toll from Tuesday’s earthquake in Pakistan has reached at least 270. Hundreds of mud homes collapsed on their inhabitants in the remote area of Quetta. Thousands of people were wounded and left homeless. It is Pakistan’s worst earthquake since 2005, when around 75,000 people were killed.

Republican Sen. Ted Cruz is staging a marathon filibuster as part of his campaign against the Affordable Care Act. The Democrat-controlled Senate is set to strip a provision from a House Republican spending bill that would tie the aversion of a government shutdown to the defunding of “Obamacare.” In his bid to stall the Senate process, Cruz began speaking Tuesday afternoon and continued into Wednesday morning. As Democracy Now! broadcasts, the filibuster is in its 17th hour. During his comments, Cruz compared those who oppose efforts to repeal “Obamacare” to the Western appeasement of Nazi Germany.

Sen. Ted Cruz: “You go to the 1940s, Nazi Germany. Look, we saw in Britain Neville Chamberlain, who told the British people, 'Accept the Nazis. Yes, they'll dominate the continent of Europe, but that’s not our problem. Let’s appease them. Why? Because it can’t be done. We can’t possibly stand against them.’”

A number of leading Republicans have opposed Cruz’s effort, fearing voters will blame their party for a government shutdown. The longer Cruz holds up a vote, the less time Republicans will have to craft a response when the Senate sends the bill back to the House. Federal agencies will be forced to close at least partially unless Congress can approve new spending before the end of the month.

Enrollment for health coverage under the Affordable Care Act is set to begin October 1. The White House has unveiled new figures showing most healthcare premiums will cost less than previously projected. The average mid-tier plan will cost $328 a month, with most qualifying for government subsidies to lower the price.

The Senate has unanimously confirmed the first openly gay judge for a federal appellate court. Todd Hughes, a Justice Department lawyer, was confirmed Tuesday for the U.S. Court of Appeals for the Federal Circuit in a 98-to-0 vote. While Hughes was confirmed, the nomination of the first gay African American to the federal bench has been defeated following an abrupt reversal by Republican Sen. Marco Rubio. Rubio has announced he is withdrawing his support for Judge William Thomas after initially backing his nomination last year. In a statement, a Rubio spokesperson cited “questions about [Thomas’] judicial temperament and his willingness to impose appropriate criminal sentences.” But critics say Rubio decided to abandon Thomas in a bid to appease tea party Republicans opposed to his backing of immigration reform. Rubio’s move will effectively end Thomas’ candidacy because nominees must have the support of both senators in their home state.

An attorney for survivors of a U.S. drone attack in Pakistan says he is being blocked from traveling to the United States to help his clients appear before Congress. Shahzad Akbar of the British group Reprieve says the State Department has approved the survivors’ travel visas, but not his. Akbar has been a vocal campaigner against the U.S. drone war, representing more than 150 survivors and their families in lawsuits against the United States and Pakistani governments. His clients, Rafiq ur-Rehman and Rehman’s two young children, are set to testify at a House hearing on drone strikes overseas. Both children were injured in an attack last October that also left their grandmother dead.

A leading Yemeni activist has been released after he was detained at a British airport and interrogated about his human rights work. Baraa Shiban, who works for the British legal charity Reprieve, was traveling to London for a speaking event Monday night when British officials detained him under Schedule 7 of the Terrorism Act — the same law that was used last month to detain David Miranda, partner of Guardian journalist Glenn Greeenwald. According to Reprieve, officials threatened to detain Shiban for the full nine hours allowed under the law after he said he did not believe his views on human rights were relevant to security. Shiban has testified before Congress about the impact of U.S. drone attacks in Yemen.

Brazilian President Dilma Rousseff has openly criticized U.S. spying on her government in a speech to the U.N. General Assembly. On Tuesday, Rousseff accused the United States of violating human rights and international law by spying on Brazilian companies, politicians and citizens.

Brazilian President Dilma Rousseff: “We are a democratic country, surrounded by democratic, peaceful countries that respect international law. We have been living in peace with our neighbors for more than 140 years. Like so many other Latin Americans, I myself fought on a firsthand basis against arbitrary behavior and censorship, and I could therefore not possibly fail to uncompromisingly defend individuals’ rights to privacy and my country’s sovereignty.”

Rousseff recently cancelled a trip to Washington in response to leaks from Edward Snowden showing the National Security Agency spied on her personal communications, as well as on Brazil’s state-run oil company, Petrobras.

The Greek government has launched a probe of the neo-Nazi Golden Dawn party in the aftermath of the killing of a prominent hip-hop musician. Rapper Pavlovs Fissass was stabbed to death by a Golden Dawn supporter outside a café last week. The murder has sparked a new wave of protests against Golden Dawn, which placed third in last year’s Greek election. On Tuesday, Greek hip-hop artists came together for an event honoring Fissass’ life. Rapper Nikitas Klint said Greeks are united against facism.

Nikitas Klint: “It was a very great moment to be united, to forget about our differences and agree on one fact: that neo-Nazis and fascism is not tolerated. We have to be more tolerant as a society towards everybody who is different, and not tolerant at all to the people who are ready to kill.”

On Tuesday, Greek police raided the Golden Dawn’s headquarters and arrested a police officer working as a bodyguard for a party lawmaker. The ongoing probe is focusing on ties between law enforcement and Golden Dawn politicians.