Negotiating teams from the U.S. and Iran could return to Islamabad later this week, five sources said on Tuesday, days after the highest-level talks between the two ‌countries in decades ended without a breakthrough.

A source involved in the talks said ​a date was not yet decided, but both countries could return as early as the end of this week.

"No firm date has been set, ⁠with the delegations keeping Friday through Sunday open," a senior Iranian source said.

The weekend ​meeting in Pakistan's capital to resolve the conflict between the U.S. and Iran, held four ⁠days after last Tuesday's ceasefire announcement, was the first direct encounter between U.S. and Iranian officials in more than a decade, and the most senior engagement since Iran's 1979 Islamic Revolution.

A proposal has been shared with both ‌the U.S. and Iran to resend their delegates to resume the talks, the ​first source said.

Two Pakistani ‌sources with knowledge of the talks said Islamabad was communicating with the two sides about the timing of the next round ‌and the meeting would likely take place on the weekend.

"We have reached out to Iran and we got a positive response that they will be open to a second ⁠round of talks," a senior Pakistani government ‌official said.

Pakistan's foreign ministry, military ⁠and prime minister's office did not respond to a Reuters request for comment. The White House also did not immediately ⁠respond ⁠to a request for comment.

U.S. Vice President JD Vance and Iranian Parliamentary Speaker Mohammad Baqer Qalibaf led their respective delegations in ‌the last round of talks to work out a slew of issues, including the Strait of Hormuz, a major transit point for global energy supplies that Iran has effectively blocked but the U.S. ‌has vowed to ​reopen, as well as Iran's ‌nuclear program and international sanctions on Tehran.

Vance told reporters after the talks ended that "We leave here with a very simple proposal, a method of understanding that is our ​final and best offer."

"We'll see if the Iranians accept it."