U.S. President Donald Trump said Friday that he and Russian President Vladimir Putin made “significant progress” at their historic summit in Alaska, though they fell short of reaching a deal to end the war in Ukraine.

Putin and Trump struck upbeat notes after they met behind closed doors for more than three hours, with the U.S. president saying they "had a very productive meeting."

"There were many, many points that we agreed on, most of them, I would say, a couple of big ones that we haven't quite gotten there, but we've made some headway. So, there's no deal until there's a deal," Trump said, indicating he would soon call Ukrainian President Volodymyr Zelenskyy and European leaders to apprise them of the talks.

"There are just a very few that are left. Some are not that significant. One is probably the most significant, but we have a very good chance of getting there. We didn't get there, but we have a very good chance of getting there," he added.

Trump and Russia's Vladimir Putin met for about 2 1/2 half hours on Friday at a summit in Alaska that started with a handshake, a smile and a ride in the presidential limousine – an unusually warm reception for a U.S. adversary responsible for launching the largest land war in Europe since 1945.