President Obama wrapped up a nuclear summit in the Netherlands on Tuesday with a dig at Russia and a response to Republican critics of his stance on Ukraine. Obama called Russia a “regional power” that acted out of weakness in annexing Crimea. He also said Republicans have exaggerated the importance of the Ukraine crisis in relation to U.S. national security.

President Obama: “Russia is a regional power that is threatening some of its immediate neighbors, not out of strength, but out of weakness. … Russia’s actions are a problem. They don’t pose the number one national security threat to the United States. I continue to be much more concerned, when it comes to our security, with the prospect of a nuclear weapon going off in Manhattan.”

Obama’s comments come after the U.S. and its G7 allies kicked Russia out of the Group of 8.