WASHINGTON (TNND) — A U.S. naval blockade at the Strait of Hormuz went into effect Monday morning, escalating pressure on Iran after peace talks over the weekend fell apart.

President Donald Trump promised to stop the negotiations to cut off revenue to Iran after negotiations yielded nothing.

“We can’t let a country blackmail or extort the world, because that’s what they’re doing, they’re blackmailing the world, we’re not going to let that happen,” Trump told reporters Monday.

Trump also warned on Truth Social that Iranian ships trying to interfere with the blockade would face strikes similar to those that have targeted and destroyed alleged drug boats. He wrote in part: “Warning: If any of these ships come anywhere close to our BLOCKADE, they will be immediately ELIMINATED.”

Even as the blockade began, Trump said talks between the U.S. and Iran continue.

“We’ve been called by the other side, they’d like to make a deal very badly. Very badly,” he said.

The blockade cuts off tankers headed to or coming from Iranian ports, while other countries’ ports remain open. Strait traffic remained limited Monday, with Iran threatening other countries’ ports over the blockade.

The Wall Street Journal reported that Trump continues to mull striking Iran again after negotiations fell through.

Sen. Tom Cotton, R-Ark., said the U.S. would respond if Iran acts on threats against regional ports.

“Well, if Iran follows through on its threat this morning to target ports in the region for our friends in places like Saudi Arabia or the United Arab Emirates, obviously, we are not going to sit back idly and let that happen. We will re-engage in part to help protect our troops and our ships in the region. Help protect our friends as well,” Cotton told Fox News Monday morning.

Peace talks fell apart over differences with Iran’s nuclear program. Axios reported the U.S. demanded Iran put a 20-year moratorium on enriching uranium and remove already enriched uranium from the country. Iran countered with a moratorium in the single digits, and the issue remained a sticking point.