Washington. US and Iranian negotiators reached a tentative agreement Thursday to extend the ceasefire in the 3-month-old war by 60 days and launch talks on Iran’s nuclear program, according to a US official familiar with the matter.

Iran did not immediately confirm any deal, and the official noted that President Donald Trump has yet to sign off on it.

The emerging memorandum of understanding came as the fragile ceasefire in the war between the United States and Iran appeared to be wavering. The latest flare-up in fighting happened less than a day earlier, when Kuwait intercepted missiles fired from Iran, according to US Central Command.

The official who described the tentative agreement was not authorized to comment publicly and spoke on condition of anonymity. Another US official, who also spoke on condition of anonymity to discuss the private diplomacy, said the broad outlines of an agreement have been reached but stressed that until Trump signs off on it, there is no deal. The official said there are still questions about whether Trump will accept the proposal.

Details of the tentative pact were first reported by the news outlet Axios.

Kuwait had earlier announced an attack on its territory, and Iran said it had retaliated for strikes earlier in the week by firing on a US base in a Gulf state it did not name. The Kuwaiti Foreign Ministry condemned Iran for what it called “blatant aggression," and US Central Command called the attack on one of America’s top allies in the Persian Gulf an “egregious ceasefire violation.”

The exchange unfolded after US officials said late Wednesday in Washington that American forces launched more strikes on Iran, shooting down four one-way attack drones that posed a threat around the Strait of Hormuz and hitting an Iranian ground-control station in Bandar Abbas that was about to launch a fifth drone.

Washington and Tehran have repeatedly accused each other of violating the seven-week ceasefire and have traded strikes throughout the week. But they have not returned to full-scale hostilities and have kept negotiating. Trump has insisted he’s confident that his administration is making headway in the talks.

On Monday, the US said it conducted what the Pentagon called “self-defense” strikes on missile launch sites and minelaying boats in southern Iran.

After the latest American strikes, Iran’s paramilitary Revolutionary Guard acknowledged the attack around Bandar Abbas International Airport. The Iranian force said via the state-run IRNA news agency that it launched a retaliatory attack on the air base that launched the assaults, without specifying whether the retaliation targeted Kuwait, which is home to US Army Central’s forward headquarters, air bases, and a naval base.