The announcement came as talks set to take place between U.S. and Iranian delegations in Pakistani were postponed amid uncertainty about the broad strokes of a deal.

Tension is building over whether the U.S. and Iran will hold a second round of peace talks in Pakistan. Bradley Blackburn reports.

The next phase of peace talks is uncertain after Iran says it has "no plans for the next round" of negotiations.

The US is waiting on whether Iran will take part in a second round of talks before a ceasefire expires on Wednesday, with the sides deadlocked on how to end a war that’s engulfed the Middle East and triggered a growing energy crisis.

Tensions in the Straight of Hormuz escalated as a ceasefire with Iran is set to expire. CBS News correspondent Natalie Brand reports.

Iranian Foreign Minister Abbas Araqchi said that "continued violations of ‌the ceasefire" by the U.S. are a major obstacle to continuing the diplomatic process.

A two-week ceasefire between Iran and the US is set to expire on Wednesday. The two countries have accused each other of breaching the ceasefire.

Iranian state television has issued an on-screen alert saying that “no delegation from Iran has visited Islamabad