The Kremlin said that the meeting in Moscow between Vladimir Putin and Donald Trump's envoy Steve Witkoff was "useful and constructive," two days before the expiry of the US ultimatum to end the conflict in Ukraine.

US President Donald Trump, who boasted that he could end the conflict within 24 hours of taking office, gave Russia until Friday, August 8, to make progress towards peace, otherwise new sanctions would be imposed.

However, three rounds of talks between Russia and Ukraine in Istanbul failed to produce any progress on a ceasefire, with the two sides remaining far apart on their demands.

Russia has escalated its drone and missile attacks against its pro-Western neighbor to record levels and accelerated its advance on the ground.

"A very useful and constructive conversation took place," Putin's adviser Yuri Ushakov said after the three-hour meeting.

Putin and Whitcoff exchanged "signals" on their positions, Ushakov said, without giving details, AFP reported.

The Kremlin released a video showing Putin and Whitcoff shaking hands at the start of the meeting.

Before the talks, Ukrainian President Volodymyr Zelensky called on Washington to increase pressure on Moscow to agree to a ceasefire.

The White House has not specified what measures it will take against Russia, but Trump has already threatened to impose "secondary tariffs" on key Russian trading partners such as China and India.

Such a measure would be aimed at stifling Russian exports, but would risk causing significant international turmoil.

Trump said he would wait for the results of the talks in Moscow before imposing economic sanctions.

"We'll see what happens. We'll make a decision then," he said.

Without explicitly naming Trump, the Kremlin condemned the "threats" to increase tariffs on Russia's trading partners as "illegal."

Russia's campaign against Ukraine since February 2022 has claimed the lives of tens of thousands of people, destroyed large parts of the country, and forced millions to flee their homes.

Moscow is demanding that Ukraine cede more territory and renounce Western support if it wants an end to the fighting.

Kyiv wants an immediate ceasefire, and Zelensky last week called on his allies to push for a "regime change" in Moscow.

"It is very important to strengthen all levers in the arsenal of the United States, Europe, and the G7 so that the ceasefire can take effect immediately," Zelensky wrote on social media after Whitford landed in the Russian capital.

"Ukraine sees the political will, appreciates the efforts of our partners, America and all those who are helping," he added.

In recent weeks, Trump has expressed growing dissatisfaction with Putin over Russia's relentless offensive.

When reporters asked the US president what Whitford's message to Moscow would be, Trump replied: "Yes, make a deal so that people stop dying."

Kremlin spokesman Dmitry Peskov said Russia considered the talks with Witkoff "important" and appreciated US efforts to end the conflict.

The visit comes at a time of heightened tensions between Moscow and Washington.

Trump announced that he had ordered the deployment of two nuclear submarines following an online dispute with former Russian President Dmitry Medvedev, which are now "in the region."

It is unclear whether Trump was referring to submarines carrying nuclear weapons or simply submarines with nuclear propulsion. He also gave no details of their deployment locations, which are kept secret by the US military.

In its first comments on the deployment of the submarines, Russia called for "caution."

Moscow announced that it was ending its self-imposed moratorium on medium-range missiles capable of carrying nuclear warheads, hinting that it could deploy such weapons in response to what it sees as a similar deployment of weapons by the US near Russia. | BGNES