Amid signs of strain in the US-Iran ceasefire over the Israeli attacks in Lebanon, President Donald Trump said on Wednesday that US military forces will remain deployed in and around Iran until Tehran fully complies with the “real agreement,” warning that any breach would trigger a military response larger than anything seen before.

Oil prices that dipped on Wednesday on optimism over the temporary ceasefire agreement jumped again after Trump’s warning.

Brent crude, the international standard, was up 3.5% to $98.09 per barrel. Benchmark US crude was 3.6% higher on Thursday at $97.83 a barrel, according to an AP report.

Global oil prices have climbed past $100 a barrel since Iran’s retaliation stalled deliveries of oil out of the Middle East.

The Strait of Hormuz, a chokepoint for energy transport where a fifth of the world’s oil typically passes, was largely closed even though the US repeatedly demanded that it must be reopened. Wednesday’s message sent a troubling signal to the oil industry.

“All US ships, aircraft, and military personnel…will remain in place in, and around, Iran, until such time as the REAL AGREEMENT reached is fully complied with,” Trump wrote on Truth Social.