Ukraine's President Volodymyr Zelensky on Tuesday urged US counterpart Donald Trump to help secure a meeting with Vladimir Putin in Turkey on Thursday, accusing the Russian leader of not seriously wanting to negotiate an end to the war.

Zelensky told reporters in Kyiv that the West should impose massive sanctions if Putin skips the meeting, emphasising that he would do "everything" possible to make it happen and secure a ceasefire.

US Secretary of State Marco Rubio will be in the US delegation at the talks which "could see some pretty good results," Trump said in Riyadh as he started a four-day Middle East trip.

The Kremlin has refused to say whether Putin will travel to Turkey, after he himself proposed Russia-Ukraine talks in a late-night Kremlin address at the weekend.

"This is his war," Zelensky said in an evening address, "therefore, the negotiations should be with him," he added.

Any meeting between Russian and Ukrainian officials would be the first direct negotiations since the early months of Moscow's operation began in February 2022.

Trump came to office in January promising a swift end to the war but has become increasingly frustrated at what he sees as the failure of Kyiv and Moscow to compromise over the bloodshed.

"I do not know the US president's decision, but if he confirms his participation, I think it would give additional impetus for Putin to come," Zelensky said at a press conference.

Trump said on Monday that he was "thinking" about going to the talks.

Zelensky said Putin was not serious about peace.

"Putin does not want the war to end, does not want a ceasefire, does not want any negotiations," Zelensky said, adding however that he "will do everything to ensure that this meeting takes place."

Putin's spokesman has repeatedly refused to say who Moscow would send to the talks.

"Our delegation will be there and will wait for the Ukrainian side," Dmitry Peskov, told state TV, adding that he would only reveal the delegation members after Putin "gives the order."

Putin spoke at a business forum and then at a cultural meeting, but did not say anything on the talks in Turkey. (AFP)