WASHINGTON, April 7 (AFP) - The US Senate voted unanimously Thursday (Apr 7) to end normal trade relations with Moscow and codify the ban on Russian oil, as the White House ratcheted up pressure on President Vladimir Putin over his invasion of Ukraine.

The legislation, which would enable Western nations to inflict steep tariff hikes on Russian goods, now heads back to the House, which is expected to take it up later in the day.

President Joe Biden announced the step in a speech last month arguing that Russia must "pay the price" for the bloodshed in its ex-Soviet neighbor, where it has denied accusations of committing atrocities.

"Putin must absolutely be held accountable for the detestable, despicable war crimes he is committing against Ukraine: the images we have seen coming out of that country... are just pure evil," said Senate Majority Leader Chuck Schumer.

"It reminds us of the worst moments in human history, caused by the evil man, Putin: hundreds of civilians murdered in cold blood."

A key principle of the World Trade Organization, the so-called most favored nation status known in the United States as permanent normal trade relations (PNTR), requires countries to guarantee one another equal tariff and regulatory treatment.

The latest trade sanctions - which also apply to Russia's ally Belarus - cap several rounds of measures intended primarily to sever Moscow's economic and financial ties with the rest of the world.

A key principle of the World Trade Organization, the so-called most favored nation status known in the United States as permanent normal trade relations (PNTR), requires countries to guarantee one another equal tariff and regulatory treatment.

The latest trade sanctions - which also apply to Russia's ally Belarus - cap several rounds of measures intended primarily to sever Moscow's economic and financial ties with the rest of the world.

The United States moved Wednesday to block foreign investment in Russia and state-owned enterprises and levied further sanctions on the country's banks and senior officials.

Secretary of State Antony Blinken told NBC News that global punishments had put the Russian economy into a "deep recession."

"And what we're seeing is a likely contraction of the Russian economy by about 15 per cent," he said.

"That is dramatic ... We've seen an exodus from Russia of virtually every major company in the world. And Putin, in the space of a matter of weeks, has basically shut down Russia to the world."