US President Donald Trump has said that discussions aimed at ending the Russia-Ukraine war were progressing positively, pointing to a "very good conversation" in Abu Dhabi.

"Ukraine and Russia, and by the way, we're having a very good conversation about that in Abu Dhabi," Trump told reporters at the White House on Monday.

Russian, Ukrainian and US representatives are scheduled to convene in the Emirati capital Abu Dhabi for a renewed round of trilateral peace negotiations starting Tuesday.

"We're also seeing a very strong inclination to end Russia and Ukraine (war). We're involved in that because I want to see people stop getting killed again," Trump said.

On the eve of the talks, President Volodymyr Zelenskyy said that Ukrainian successes on the battlefield strengthened Kiev's position in the negotiations.

"Ukrainian forces are currently genuinely strengthening Ukraine's negotiating position," Zelenskyy said in his nightly video address.

"Every task that is fully accomplished, every defensive operation that increases Ukraine's strength and delivers results, strengthens Ukraine and, above all, strengthens us in negotiations."

Ukraine's focus

Earlier, Zelenskyy's chief of staff, Kyrylo Budanov, said while on his way to Abu Dhabi that maintaining the diplomatic process was important at the talks and Kiev would focus on prisoner exchanges and other humanitarian issues.

Zelenskyy said the delegation will propose de-escalatory steps, urging that “there must be an understanding of how to arrange a trilateral meeting at the leaders’ level to bring this war to an end fairly and for real.”

Ukraine's delegation to the talks is being led by Rustem Umerov, the head of foreign intelligence.

The talks with Russian and US negotiators will be the first since February aimed at bringing an end to the more than 4-1/2-year-old war.