WATCH: ‘Nothing set in stone,’ Trump says aboard Air Force One en route to meeting with Putin

President Donald Trump said Friday that he wants to negotiate an end to Russia’s war in Ukraine with President Vladimir Putin, but also said that his goals were not “set in stone.”

Watch Trump’s remarks in the video player above.

Speaking aboard Air Force One on his way to meeting with Putin in Alaska, Trump told reporters he wants “to see a ceasefire rapidly.”

Putin is a “smart guy,” Trump said. “He’s been doing it for a long time. But so have I,” he added.

LIVE UPDATES: Trump meets with Putin in Alaska

Trump said that while Europe wouldn’t dictate the terms of any agreement, they would be involved in the process.

The president said that any security guarantees for Ukraine would not come from NATO, but reiterated that he wants the violence and the war to end.

“The war’s got to stop, and the killing’s got to stop,” Trump said.