The UK will ban Russian oil imports by the end of this year as Vladimir Putin has shown no signs of halting his invasion of Ukraine.
The move follows pleas from Ukrainian President Volodymyr Zelensky to western officials to cut off Russian imports.
Business Secretary Kwasi Kwarteng said the transition would "give the market, businesses and supply chains more than enough time to replace Russian imports - which make up 8% of UK demand".
But Boris Johnson did not set out plans to wean the UK off Russian gas after energy costs spiralled. Officials insisted Russian gas makes up less than 4% of the UK supply.
US President Joe Biden has gone a step further, announcing a ban on Russian oil and gas imports this afternoon.
Mr Biden described his move as a "powerful blow" to "Putin's war" and claimed Americans that "defending freedom is going to cost".
Energy exports keep a steady influx of money flowing to Moscow, even with sanctions imposed by Western nations.
The Business Department said oil makes up 44% of Russian exports and 17% of the country's federal government revenue through taxes, striking a major blow to Moscow.
Only 13% of the UK's oil imports were from Russia in 2020.
News that Mr Johnson was going to make an announcement on energy was first reported by Politico, citing three Whitehall officials. It was later confirmed.
The European Union is committed to phasing out its dependency on Russian energy as soon as possible.
EU officials are expected to cut Russian gas imports by nearly two thirds within a year, according to reports.
The news follows the PM's promise to set out a "energy supply strategy" to reduce the UK's reliance on Russian gas.
Mr Johnson yesterday admitted he can't "shut off" the UK's dependency on Putin's resources overnight, but said the UK move "faster" than other Western nations.
Speaking alongside the prime minister's of the Netherlands and Canada, Mr Johnson said: "We need to increase our self-reliance.
"There are going to be impacts but I think it is the right thing to do. It is completely the right thing to do, to move away from Russian hydrocarbons but we have to do it step by step."
Russian ships were banned from UK ports on March 1 and authorities were granted new powers to detain Russian vessels, the government said.
