Time is ticking on President Donald Trump's two-week timeline for a face-to-face meeting between Russian President Vladimir Putin and Ukrainian President Volodymyr Zelenskyy.

Just a handful of days after his summit with Vladimir Putin, the US president told Volodymyr Zelenskyy that Ukraine would receive substantial security guarantees as part of the future deal. However, Trump did not specify what it is that Ukraine will be asked to give in exchange.

President Donald Trump says he'd back European security guarantees for Ukraine, though he stopped short of committing U.S. troops to the effort during talks with President Volodymyr Zelenskyy at the White House to bring an end to Russia’s war on Ukraine.

Ukraine and its European allies have been buoyed by Trump's promise during a summit on Monday of security guarantees for Kyiv, but many questions remain unanswered. Officials told Reuters that the Pentagon is carrying out planning exercises on the support Washington could offer beyond providing weapons.