Efforts by regional countries, including Pakistan, to broker a cease-fire between the United States and Iran have stalled, with Tehran rejecting planned talks in Islamabad and dismissing U.S. demands as unacceptable, according to a report Friday.

Iran has officially told mediators that it is unwilling to meet U.S. officials ⁠in Islamabad in the coming ​days and considers U.S. ​demands unacceptable, ⁠the ‌Wall Street Journal report ‌said.

The U.S. proposed a 48-hour cease-fire with Iran on April 2 through a third country, the semi-official Fars News Agency reported Friday, citing an informed source.

"The US, on April 2, proposed a 48-hour ceasefire through one of the friendly countries," the source told Fars.

The proposal came after "escalating tensions and challenges faced by US forces in the region," the source added.

According to the news agency, Iran did not respond in writing but instead replied "on the ground" by continuing heavy attacks.

The source also said that "US diplomatic efforts to halt the fighting have intensified, particularly after a reported strike on a US military depot on Bubiyan Island in Kuwait."

The war has threatened global supplies of oil, natural gas and fertilizer and disrupted air travel. Iran's grip on the strategic Strait of Hormuz has shaken markets and prices.

China and Pakistan laid out a five-point Mideast plan to end the Iran war earlier this week. The plan calls for an end to attacks on civilians and non-military targets, such as energy infrastructure and desalination plants.

Shipping lanes should be secured, allowing "the early and safe passage of civilian and commercial ships" through the strategic Strait of Hormuz, it added.

Both countries said a lasting peace should be based on the U.N. charter and international law.