President Joe Biden is expected to announce a ban on US imports of Russian oil and gas Tuesday, in a further tightening of unprecedented economic sanctions punishing Moscow over its invasion of Ukraine.

The ban is partly a response to strong bipartisan pressure from Congress, despite the impact the announcement is likely to have on already soaring domestic gas prices.

The White House said the president would speak at 1545 GMT to "announce actions to continue to hold Russia accountable for its unprovoked and unjustified war on Ukraine."

According to US media reports, the ban will include Russian oil and liquefied natural gas. Washington's European allies, who are for more reliant on Russian energy than the United States, will not participate -- at least for now.

Russia accounts for less than 10 percent of US imports of oil and petroleum products, which means the impact on the world's largest economy would be easier to bear.

While rising oil prices have added to inflation concerns, undermining Biden's approval among voters, Democratic House Speaker Nancy Pelosi supports an oil ban as well as raising tariffs on other Russian goods to "further isolate Russia from the global economy."

However, she also favors steps to lower oil prices, including releasing more crude from the US strategic petroleum reserve.

"Let me be clear: the United States need not choose between our democratic values and our economic interests," she said in a letter to legislators.

Even without a ban, oil prices have risen about 30 percent in response to the Russian invasion, and Brent crude futures were nearly $130 on Tuesday. 

Prices at the pump jumped to $4.17 on Tuesday, according to the American Automobile Association (AAA) national average, compared to $3.46 a month ago.

"Bottom Line is that the USA would feel some impact to the loss of supplies from Russia, but we are in a far better position than Europe," energy analyst Andy Lipow said.

Senator Chris Coons, from Biden's home state of Delaware, warned that Europe "will see dramatic increases in prices" since production cannot ramp up suddenly.

"That is the cost of standing up for freedom and of standing alongside the Ukrainian people. But it is going to cost us," he said on CNN on Tuesday.