Oil surges 6% after Trump says ceasefire with Iran is over

Oil prices spiked Wednesday after U.S. President Donald Trump said the U.S. ceasefire with Iran is over.

West Texas Intermediate futures for August delivery rose 6.25% to $74.83 per barrel. Futures for International benchmark Brent crude for September delivery jumped 6% to $78.64 per barrel.

During a joint press conference with NATO chief Mark Rutte at the military alliance's summit in Ankara, Turkey, on Wednesday, Trump was asked whether the U.S.'s ceasefire with Iran was over.

"To me, I think it's over," he said. "I don't want to deal with them anymore … as far as I'm concerned, it's over."

He added that Washington's delegation wanted to negotiate a peace deal, but that he saw it as "a waste of time dealing with" the Iranian side.

WTI Crude

Trump's comments came after the U.S. military conducted a "series of powerful strikes" against Iran in retaliation for three commercial vessels transiting the Strait of Hormuz coming under attack on Tuesday. Washington warned at the time that Tehran would face "heavy costs" for targeting commercial shipping.

"Strikes are in response to Iranian attacks on three commercial vessels that were transiting the Strait of Hormuz. Iran's demonstrated aggression was unwarranted, dangerous, and a clear violation of the ceasefire," the U.S. Central Command said in a post on X. 

A ceasefire reached between the two sides last month reopened the critical Strait of Hormuz for commercial shipping after months of disruption.

Signaling that things have taken a turn for the worse, the U.S. Treasury Department on Tuesday withdrew a waiver that had allowed Iran to sell its oil.

"Iran will only reap benefits if they exhibit good behavior," a U.S. official told CNBC, speaking on condition of anonymity to discuss private talks. "Iran's actions in the Strait were wholly unacceptable to the United States and will be met with consequences."

In a statement earlier Wednesday, Iran's foreign ministry labeled the strikes a "gross violation of the Memorandum of Understanding" Washington and Iran reached last month to bring their war to an end.

"The powerful armed forces of the Islamic Republic of Iran, as they have repeatedly shown, will not hesitate to defend Iran's territorial integrity, national sovereignty, and national security against American military aggression," the ministry said, according to a Google translation.

Three vessels were attacked in or near the Strait of Hormuz on Tuesday, according to the U.S.-led Joint Maritime Information Center, which raised its threat assessment for ships transiting the waterway to "severe," warning that further hostile action by Iran was likely.

"It's not in Iran's best interest to settle on a deal with their leverage over Trump only increasing the closer we get to November, although yesterday's attacks coincide with the ongoing state funeral ceremonies for Ali Khamenei," said Andrew Jackson, a strategist at Ortus Advisors.

The U.S. midterm elections are due in November, and Mideast conflict-induced inflation stands to raise the political stakes for the Trump administration.

"The corresponding jump in oil and yields and likelihood that the Fed will be forced to take a more hawkish stance with inflation here to stay," he said in an email. The 10-year Treasury yield was trading 5 basis points higher at 4.581%.

— CNBC's Spencer Kimball and Megan Cassella contributed to this report.