US and European officials will immediately work on providing Ukraine with robust security guarantees to open a path for a landmark meeting between presidents Vladimir Putin and Volodymyr Zelenskiy, according to people familiar with the matter.

Plans for security guarantees for Ukraine appear to be triggering unease in Moscow, which repeated objections to any role for forces from NATO countries.

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.

Not even a full day after hosting European leaders who expressed solidarity with Ukraine, Trump on Tuesday reverted to his usual pro-Putin self.

Emerging-market currencies in central and Eastern Europe advanced on Tuesday after signs of progress toward peace talks between Russia and Ukraine, with US President Donald Trump encouraging the leaders of both countries to hold a bilateral summit.