President Trump said he spoke by phone with Russian President Vladimir Putin about the war in Ukraine and other issues.
"We both reflected on the Great History of our Nations,"
Trump said in a post on his Truth Social social media platform.
"We agreed to work together, very closely, including visiting each other's Nations. We have also agreed to have our respective teams start negotiations immediately, and we will begin by calling President [Volodymyr] Zelenskyy, of Ukraine, to inform him of the conversation, something which I will be doing right now," he said.
The comments came Wednesday as Trump's new defense secretary, Pete Hegseth, laid out the administration's ideas about European defense and the war in Ukraine in a meeting in Brussels.
Hegseth said the United States will no longer be "primarily focused" on European security, saying Europe should take on greater responsibility for its own defense, particularly when it comes to support for Ukraine.
He also said the possibility of Ukraine joining NATO and the restoration of Ukraine's pre-2014 borders were "unrealistic."
"The United States does not believe that NATO membership for Ukraine is a realistic outcome of a negotiated settlement,"
he said.
Hegseth was speaking to Ukraine's backers gathered for a meeting at NATO headquarters in Brussels.