Trump didn't rule out the possibility of American troops' helping to guarantee peace between Ukraine and Russia should the leaders reach an agreement.

Moscow continues to throw cold water on the prospect of Putin-Zelenskyy meeting, and is insisting Russia have a role in security guarantees for Ukraine.

Russian president Vladimir Putin is reportedly willing to freeze current front lines in exchange for Ukrainian territorial concessions and a NATO membership ban.

In the most detailed Russian-based reporting to date on Putin's offer at the Alaska summit, Reuters was able to outline the contours of what the Kremlin would like to see in a possible peace deal.

The Donbas region in eastern Ukraine has long been contested by Russia, with military aggression forcing 1.5 million Ukrainians to flee over the past decade. Ukraine has consistently rejected conceding Donbas to the Kremlin in exchange for peace, though Trump stressed the need for "swapping of territories".

Russia's top military and political officials joined Putin in the closed city of Sarov, which houses the Russian Federal Nuclear Center, on Aug. 22.

Russia’s top diplomat said in an interview released on Friday that “there is no meeting planned” between President Vladimir V. Putin of Russia and President Volodymyr Zelensky of Ukraine, the clearest sign yet that a summit the White House had said was imminent is nowhere close to materializing.

Ukrainian President Volodymyr Zelenskyy said he wants a "strong reaction" from the U.S. if Russian President Vladimir Putin does not sit down with him for a bilateral meeting.