09:14 AM EDT, 03/31/2025 (MT Newswires) -- Oil prices rose early on Monday after U.S. President Donald Trump threatened to impose secondary tariffs on buyers of Russian oil as Vladimir Putin, his Russian counterpart, continues to violate a ceasefire agreement with Ukraine brokered by the United States.

West Texas Intermediate crude oil for May delivery was last seen up US$0.37 to US$69.73 per barrel, while May Brent crude was up U$0.61 to US$74.24.

Trump on Sunday said he may impose tariffs of up to 50% on U.S. imports from countries buying oil from Russia if Putin does not comply with a partial ceasefire agreement for its war on Ukraine. However there are doubts Trump plans to carry through on his threats.

"In a telephone interview ... using language that we will not print, Mr Trump said he was fed up with Vladimir Putin over his attitude to the Ukraine ceasefire and indicated he would levy a 25% or 50% tariff that would affect countries buying Russian oil. He also said that bombing Iran is an option to bring the nation to the nuclear negotiating table. Such moves ought to be greeted with more of a bullish bias, but observers note that later President Trump spoke on step-by-step progress with Russia," PVM Oil Associates noted.

The threat to buyers of Russian oil follow on Trump's announced plans last week to impose tariffs on buyers of oil from Venezuela and tightened sanctions on Iran, promising tighter supply if the United States carries through on the tariffs plans.