US and Russian officials will converge on the state of Alaska ahead of a highly anticipated Friday meeting between Presidents Donald Trump and Vladimir Putin.
The pair will meet for the first time in six years, as Trump tries to enact a key campaign pledge to end Russia's war in Ukraine.
The US president, who has portrayed himself as a global peacemaker, hopes to leverage his personal relationship with Putin to achieve a ceasefire breakthrough where others have failed.
On Thursday he assessed there was a "25% chance" the meeting would not be successful.
Ukraine's leader Volodymyr Zelensky has been excluded from the talks, and warned that any resolutions made in his absence will be meaningless.
