Ammon News - Negotiating teams ​from the U.S. ‌and Iran could return ​to Islamabad ​this week, four sources ⁠said ​on Tuesday, days ​after the highest-level talks between the ​two ​countries since the 1979 ‌Islamic ⁠Revolution ended in the Pakistani capital ​without ​a ⁠breakthrough.

Pakistani Prime Minister Shehbaz Sharif said on Monday that the ceasefire between the United States and Iran remains “holding,” while efforts continue to reach an agreement following unsuccessful talks in Islamabad at the weekend.

The U.S. and Iran failed to reach an agreement to end their war despite lengthy talks that concluded on Sunday in the Pakistani capital Islamabad, ​jeopardising a fragile ceasefire.

Each side blamed the other for the failure of the 21-hour-long negotiations to end fighting that has killed thousands and sent global oil prices soaring since ‌it began over six weeks ago.

"The bad news is that we have not reached an agreement, and I think that's bad news for Iran much more than it's bad news for the United States of America," Vice President JD Vance, the head of the U.S. delegation, told reporters shortly before he left Islamabad.

JD Vance told Fox News on Monday: "I really think the ball is in the Iranian court, because we put a lot on the table. We actually made very clear what our red lines were."

The U.S. military began a blockade of Iran's ports on Monday, President Donald Trump said, and Tehran threatened to retaliate against its Gulf neighbours' ports after weekend talks in Islamabad on ending the war broke ​down.