JD Vance flying to Islamabad
The call comes amid efforts to secure a second round of talks between the US and Iran, expected to take place soon in the Pakistani capital.
Pakistan hosted the first round of US-Iran talks between April 11 and 12 after brokering a two-week ceasefire on April 8, which is set to expire by dawn on Wednesday.
Earlier, Pakistani sources said Iranian officials are expected to arrive in Islamabad on Tuesday.
The White House said Vice President JD Vance was ready to fly back to Pakistan, but Tehran kept up uncertainty on its participation, accusing the United States of violating a soon-to-expire ceasefire through its blockade of Iranian ports and seizure of a ship.
US has similarly accused Tehran of violating the truce by harassing vessels in the Strait of Hormuz, the transit passage for one-fifth of the world’s oil that Iran had all but shut in retaliation for the war launched by the United States and Israel.
Regional tensions have escalated since February 28, when the US and Israel launched a joint attack on Iran that has killed more than 1,300 people, while Tehran responded with missiles and drones targeting Israel and regional countries hosting US assets.
A total of 415 US service members have been wounded since the start of Operation Epic Fury against Iran, US Defense Department data showed on Monday.
A total of 13 US service members have been killed, according to the data.