President Donald Trump on Wednesday accused Iran of taking too long to negotiate a deal and said they would now “have to pay the price”, a day after both countries exchanged tit-for-tat strikes that threatened a fragile ceasefire.

Iran launched missile and drone attacks on US bases in Jordan, Kuwait and Bahrain in what it called retaliation for American ⁠strikes on Iranian targets around the Strait of Hormuz.

“Iran is all talk and no action,” Trump said in a social media post on Wednesday morning. “They’ve taken too long to negotiate a deal that would have been great for them, now they will have to pay the price!!!”

The U.S. military said it had targeted Iranian air defences, ground control stations and surveillance radar sites in what it described as a “proportional response” ⁠to the downing of an Apache helicopter, whose two crew members were rescued by a drone boat near the Strait of Hormuz.

In response, Iran’s Foreign Ministry spokesperson indicated that Tehran would reassess its diplomatic engagement with Washington, citing what it called repeated ceasefire violations. “Any diplomatic process requires a minimum stable environment,” Esmaeil Baghaei said.

The renewed hostilities have further jeopardised prospects for a lasting peace deal to end the conflict that began on 28 February with joint US-Israeli strikes on Iran.

Fox News, citing a phone interview, reported that Trump said he may order new strikes on Iran’s power plants and bridges because Tehran was taking too long to make a deal.

But diplomatic efforts do not appear to have ended. A delegation from Qatar, which has been mediating between the United States and Iran, landed in ‌Tehran on Wednesday to hold talks about the latest developments related to diplomatic efforts to end the war, Iranian state media reported.

The US strikes overnight lasted about four hours, with Central Command saying shortly before 9 p.m. ET that operations had ended. A US official said nearly 20 Iranian targets were hit.

Iran’s Islamic Revolutionary Guard Corps (IRGC) said Qeshm Island and the port of Sirik were attacked. Iranian media also reported explosions in Bandar Abbas, another port city, ⁠and later near Jask at the entrance to the Strait of Hormuz.

The ceasefire in early April was intended to pave the way for peace talks, with diplomats aiming to reopen Hormuz, end a US blockade of Iranian ports, and establish a framework for negotiations over Iran’s nuclear programme.

Trump has repeatedly suggested a deal is close, but despite several rounds of indirect talks mediated by Pakistan and Qatar, the two sides remain far apart.

Ongoing fighting between Israel and Iran-backed Hezbollah militants in Lebanon persists, and Tehran has maintained restrictions on shipping through the Strait of Hormuz, which historically carried a fifth of the world’s crude oil and liquefied natural gas. Washington has also maintained its own blockade.

Trump has insisted that any peace deal must prevent Iran from developing a nuclear weapon, a claim Iran denies.

Tehran’s demands include the lifting of sanctions, the release of billions in frozen assets, recognition of its control of the strait, and an end to fighting in Lebanon.