A badge with the Ukrainian flag is seen on a trooper`s arm as Ukrainian soldiers prepare to take part in a military training with French servicemen, at an undisclosed location in Poland, on April 4, 2024. (Photo by AFP)

Russia says Ukraine should pull back troops from the Donbas (Donetsk and Luhansk regions) if it wants an end to the four-year-long war between the two countries.

Kremlin spokesman Dmitry Peskov made the remarks on Monday, one day after US President Donald Trump spoke with his Russian counterpart, Vladimir Putin, over the phone and met with Ukrainian President Volodymyr Zelenskyy.

Asked about the decision Kiev needed to make regarding the Donbas, Peskov said, "We are talking about the ‌withdrawal of the regime`s armed forces from the Donbas."

According to Russian estimates, Moscow controls 90 percent of the Donbas and 75 percent of the Zaporizhzhia and Kherson regions.

Also in his comments, Peskov warned that Ukraine would lose more territory to Russia in the coming months unless a deal was struck.

He said another telephone conversation between Putin and Trump is planned "very soon," while confirming that no call between the Russian president and his Ukrainian counterpart is being discussed.

During a meeting in Florida on December 28, Zelenskyy and Trump discussed the latter`s revised 20-point plan on the Russia-Ukraine war.

Trump said a breakthrough to end the conflict was "getting a lot closer," adding, however, that there were "one or two tough" outstanding issues, including over territory.

Meanwhile, Trump said that a proposal to turn the Donbas into a demilitarized zone remains "unresolved".

Zelenskyy had earlier said he would agree to withdraw troops to create an economic zone if Russian forces did the same and the Donbas remained part of Ukraine and was monitored by an international peace force.

The Donbas, as well as the Zaporizhzhia and Kherson regions, voted to secede from Ukraine and join Russia in referendums held in September 2022.

Russia launched what it called a special military operation in Ukraine in February 2022 to prevent NATO`s eastward expansion after warning that the US-led military alliance was following an "aggressive line" against Moscow.

The Western countries have been fueling the flames of the war through the supply of advanced weaponry to Kiev.