Negotiators from Russia and the United States have met in the US city of Miami as Ukrainian President Volodymyr Zelenskyy urged Washington to ramp up the pressure on Moscow to end its war on Ukraine.

The meeting on Saturday took place between Russian President Vladimir Putin’s special envoy, Kirill Dmitriev, and US President Donald Trump’s special envoy, Steve Witkoff, and his son-in-law, Jared Kushner.

Dmitriev told the reporters the talks were positive and would continue on Sunday.

“The discussions are proceeding constructively,” said Dmitriev. “They began earlier and will continue today, and will also continue tomorrow.”

Earlier, US Secretary of State Marco Rubio had said that he may also join the talks in Miami. He said that progress has been made in discussions to end the war, but there is still a way to go.

“The role we’re trying to play is a role of figuring out whether there’s any overlap here that they can agree to, and that’s what we’ve invested a lot of time and energy [on], and continue to do so,” Rubio said. “That may not be possible. I hope it is. I hope it can get done this month, before the end of the year.”

Trump’s envoys have for weeks been negotiating a 20-point peace plan with Ukrainian, Russian and European officials.

While US ​officials say they have made progress, major differences remain on the issues of territory and possible security guarantees that Kyiv says are essential for any agreement.

Russia has shown few signs that it is willing to give up its expansive territorial demands in Ukraine, which it believes it is well-positioned to secure as the war grinds on and political fractures emerge among Ukraine’s European allies.

In Kyiv, Zelenskyy said he remains supportive of a US-led negotiations process, but that diplomacy needs to be accompanied by greater pressure on Russia.

“America must clearly say, if not diplomacy, then there will be full pressure… Putin does not yet feel the kind of pressure that should exist,” he said.

The Ukrainian leader said Washington has also proposed a new format for talks with Russia, comprised of three-way talks at the level of national security advisers from Ukraine, Russia, and the US.

Zelenskyy expressed scepticism that the talks would result in “anything new”, but said he would support trilateral discussions if they led to progress in areas such as prisoner swaps or a meeting of national leaders.

“If such a ‍meeting could be ⁠held now to allow for swaps of prisoners of war, or if a meeting of national security advisers achieves agreement on a leaders’ meeting… I cannot be opposed. We would support such a US proposal. Let’s see how things go,” he said.

The last time Ukrainian and Russian envoys held official direct talks was in July in Istanbul, which led to prisoner swaps but little else.

The talks in Miami come after Putin promised to press ahead with his military offensive in Ukraine, hailing Moscow’s battlefield gains in an annual news conference on Friday.

Putin, however, suggested that Russia could pause its devastating strikes on the country to allow Ukraine to hold a presidential ballot, a prospect that Zelenskyy rejected.

Meanwhile, the death toll in Ukraine’s Black Sea Odesa region from an overnight Russian ballistic missile strike on port infrastructure rose to eight, with 30 people wounded.

A civilian bus was struck in the attack, Ukrainian Prime Minister Yulia Svyrydenko said.

The Russian attacks on the coastline region have wrought havoc in recent weeks, hitting bridges and cutting electricity and heating for hundreds of thousands in freezing temperatures.

Moscow earlier said it would expand strikes on Ukrainian ports as retaliation for targeting its sanctions-busting oil tankers.

On Saturday, Ukraine claimed to have destroyed two Russian fighter jets at an airfield in Moscow-occupied Crimea, according to the security service SBU. Kyiv’s army said it struck a Russian oil rig in the Caspian Sea as well as a patrol ship nearby.

Putin described Russia’s initial full-scale invasion of Ukraine as a “special military operation” to “demilitarise” the country and prevent the expansion of NATO.

Kyiv and its European allies say the war, the largest and deadliest on European soil since World War II, is an unprovoked and illegal land grab that has resulted in a tidal wave of violence and destruction.