US secretary of state Marco Rubio has been speaking about the next round of trilateral talks with Ukraine and Russia in Abu Dhabi.
It comes after reports suggested they could resume on Sunday (see 14.07 post).
Speaking at a Senate foreign relations committee hearing, Rubio says there could be a US presence at the follow-up talks but it won't be Donald Trump's top envoys Steve Witkoff and Jared Kushner, who had taken part in the previous round of talks.
Providing more detail on the sticking points, Rubio says territorial issues over Donetsk still need smoothing over, adding that it's a "very difficult" topic.
Could Donetsk fall into Putin's hands?
His comments come as the Institute for the Study of War says Ukraine's Donetsk region - which alongside the Russian-held Luhansk region makes up the Donbas - will fall into Moscow's hands by August 2027 if Putin's troops sustain their rate of advance (see 10.50 post).
It says Russia "would need to expend significant amounts of resources, time, and personnel to seize the rest of Donbas".
Meanwhile, a report in the Financial Times suggests the Trump administration has indicated to Ukraine that US security guarantees are contingent on Kyiv first agreeing a peace deal that would likely cede the Donbas to Russia.
The White House has hit back against the report, calling it "totally false".