On Monday, Trump said that Russia's failure to reach a negotiated settlement with Ukraine within 50 days would lead to his administration imposing a 100% tariff rate on Russian imports as well as what he called "secondary tariffs" on countries that have continued to do business with Moscow.

Donald Trump has again warned Russia that it will face "secondary tariffs" and other sanctions if it does not agree to a ceasefire in Ukraine, but claimed he is "not on anybody's side" in the conflict

New developments Tuesday reinforced the idea that President Donald Trump has significantly shifted his view of the Ukraine war.

Sitting in the Oval Office with NATO Secretary-General Mark Rutte, and apparently fed up with being slow-walked by Russian President Vladimir Putin, Trump threatened the Kremlin with tough tariffs if it doesn't make a deal to end the war within 50 days. But perhaps more important was Trump's shift on weapons.

Russian President Vladimir Putin has sacrificed an estimated 1 million of his soldiers, killed and wounded, in a three-year campaign to crush Ukraine.

The Kremlin said on Tuesday that U.S. President Donald Trump's recent statements, including a threat of sanctions on buyers of Russian exports, are serious and require analysis.

But Putin appears to be unfazed by these latest development and is refusing to kowtow to Trump and his demands. READ MORE: NATO considers retaliation against Russia as WW3 and plane crash fears soar READ MORE: Vladimir Putin launches attack on Ukraine a day after Trump's '50 days' threat Instead the Kremlin has intensified its attacks on the White House incumbent,

Melania Trump has highlighted Russia's continued attacks on Ukraine in private conversations, President Trump said on Monday.

Vladimir Putin’s conduct has prompted Donald Trump’s shift as Russia’s war effort in Ukraine has gotten only more aggressive.

The US president spoke to reporters on the White House South Lawn on Tuesday afternoon, the day after he threatened to impose "secondary tariffs" on Moscow

"We are coping, and I have no doubt that we will cope," said Russia's foreign minister, Sergey Lavrov.