US and Ukrainian envoys issued a joint statement on Sunday that hailed "productive and constructive" talks in Miami, but did not announce any apparent breakthrough in efforts to end the war with Russia.

Top representatives of Ukraine and Russia, as well as Kyiv's European allies, have been in southern Florida over the past several days for a series of separate talks hosted by US President Donald Trump's special envoy, Steve Witkoff.

Despite a flurry of high-level meetings in recent weeks, there have been no clear signals of imminent resolutions to key hurdles on ending the nearly four-year war.

The diplomatic blitz came after Washington last month presented a 28-point plan on the war that was widely seen as echoing the Kremlin's demands.

It has since been redrafted following Ukraine and Europe's involvement, though its contents have not been publicly disclosed.

"Over the last three days in Florida, the Ukrainian delegation held a series of productive and constructive meetings with American and European partners," Witkoff and Ukraine's top negotiator, Rustem Umerov, said in separate statements on X.

They said a bilateral US-Ukraine meeting focused on developing and aligning positions on "four key documents" – a "20-point plan," a "Multilateral security guarantee framework," a "US Security guarantee framework for Ukraine" and an "economic & prosperity plan."

"Particular attention was given to discussing timelines and the sequencing of next steps," they said, without announcing any further meetings.

National security advisors from Kyiv's European allies "also joined the discussions to align on a shared strategic approach between Ukraine, the United States, and Europe," the statements added.

Russian envoy Kirill Dmitriev was also in southern Florida and believed to have met with the US delegation, which includes billionaire real estate developer Witkoff and Trump's son-in-law Jared Kushner.

A video on Russian state media showed Dmitriev arriving in a motorcade at Witkoff's Shell Bay luxury golf club.

The Kremlin on Sunday said recent proposed changes to the plan to end the war were a non-starter.

Dmitriev "should receive information about what has been developed by the Americans and Europeans" in the plan and report that back to Moscow later, Kremlin's spokesman Dmitry Peskov told state TV. (AFP)