Russia and America in 'WW3' row as Putin defies Trump and masses 50,000 troops on border with Ukraine

America and Russia clashed in a “World War Three” public row as Vladimir Putin again defied Donald Trump and massed 50,000 troops on Ukraine’s border.

The military build-up close to the northern Sumy region sparked fears that the Russian president is set to launch a summer offensive despite Trump’s efforts to get a ceasefire.

After days of heavy air attacks on Ukrainian cities, the US president warned Putin that he was “playing with fire,” though he has yet to follow through with threats of increased sanctions on Russia.

In his latest criticism, Trump posted on Truth Social: “What Vladimir Putin doesn’t realize is that if it weren’t for me, lots of really bad things would have already happened in Russia, and I mean REALLY BAD. He’s playing with fire.”

Top Russian security official Dmitry Medvedev, a former president, hit back, saying Trump should worry more about World War Three.

America’s Ukraine envoy, retired General Keith Kellogg, responded by posting on X: “Stoking fears of WW III is an unfortunate, reckless comment... and unfitting of a world power.”

As the row simmered, Putin’s foreign policy aide, Yuri Ushakov, argued Trump’s remark suggested he is “not sufficiently informed about what is really happening in the context of the Ukrainian-Russian confrontation,”. 

In an apparent sign of seeking to contain the clash, Kremlin spokesman Dmitry Peskov said it was clear the Trump administration is making “considerable efforts towards a peaceful settlement” and that Russia was “grateful for the mediation efforts of President Trump personally.”

After Russia ejected Ukrainian forces from the western Kursk region, Moscow’s forces have pushed over the border into neighbouring Sumy region of northeastern Ukraine and seized several villages.

Ukrainian President Volodymyr Zelensky said Russia has gathered 50,000 troops near the northern Sumy region, but added that Kyiv had taken steps to prevent Moscow from laumching a large-scale offensive.

Putin has repeatedly said he wants a “buffer zone” along Russia’s border with Ukraine.

After speaking to Trump on May 19 for more than two hours, the Russian president said that he had agreed to work with Ukraine on a memorandum which would set out the contours of a peace accord including the timing of a ceasefire.

But the Russian president has been accused of dragging his feet over peace moves, with Trump suggesting he may be playing him along rather than being serious about talks.

Russia said it had downed 296 Ukrainian drones over 13 regions overnight while Ukraine said Russia had launched 88 drones and five ballistic missiles.

Russian Defence Minister Andrei Belousov said that the US-led NATO military alliance was using the Ukrainian crisis to build up its presence across eastern Europe and the Baltic but that Russia was advancing along the entire front in Ukraine.

Putin ordered his full-scale invasion of Ukraine in February 2022 but Russia currently controls just under one fifth of the country.

Hundreds of thousands of Russian soldiers have been injured or killed, with similarly high casualties also among Ukraine’s forces, and thousands, if not tens of thousands, of civilians killed in often indiscriminate Russian air attacks.