The United States and Iran on Monday separately announced they will send delegations to Qatar this week, though Tehran insisted it has not agreed to meet with the U.S. “at any level” after attacks across the Persian Gulf over the weekend challenged negotiations to end the war.

U.S. President Donald Trump said the Islamic Republic had requested a meeting with U.S. counterparts and that they planned to convene Tuesday in Doha, Qatar.

But one of Iran’s senior negotiators denied talks had been scheduled. And the spokesman for Iran’s Foreign Ministry said Tehran was sending its delegation to Qatar, a key mediator in the negotiations, to discuss terms of the interim deal without involving the U.S.

The U.S. president has tried to preserve a fragile interim deal, but hostilities mounted in recent days in the Strait of Hormuz, through which a fifth of the world’s oil had been shipped before war began. After four days of trading strikes, both sides appeared to pause their attacks Monday.

The U.S. and Iran agreed to an interim deal earlier this month that calls for Tehran to dilute its stockpile of enriched uranium. It also waives U.S.-backed sanctions on the country, opens the Strait of Hormuz and gives each side 60 days to hammer out broader agreements.