Oil surged by the most since April after U.S. President Donald Trump said he would reimpose a blockade on Iranian ships transiting the Strait of Hormuz and demand payment for all other cargo moving through the waterway, dashing hopes for a near-term recovery in shipping flows.

West Texas Intermediate futures jumped 9.4% to settle near $78 a barrel, the highest in nearly a month, while Brent closed above $83. Prices extended gains in post-settlement trading after Trump said the U.S. will strike Iran ¡°very hard¡± overnight Monday and on Tuesday. Brent was over 10% higher than Friday¡¯s closing price.

The moves fueled bullish momentum further after the U.S. and Iran traded strikes over the weekend, including attacks on some energy infrastructure, all but extinguishing hopes that a mid-June thaw in tensions would lead to a normalization of traffic through Hormuz.