Monday was the deadline for Iran and the U.S. to reach a final agreement based on the memorandum signed on June 17 to end the war.

No agreement was announced today, and both sides sent different messages as tensions continued to rise.

A senior Iranian official told Reuters today that Iran has shifted its policy from a defensive stance to a "fully aggressive" one amid a deadlock in efforts to achieve a permanent end to the war with the U.S.

The official warned that Iran is prepared to escalate tensions in the Strait of Hormuz and the wider region, adding that if diplomacy fails, Tehran will carry out a "timely and precise" military strike to break the U.S. maritime blockade.

The official told Reuters: "Within the short timeframe of a few weeks that Iran has set, all provisions of the agreement must be implemented by the U.S. This is a precondition for continuing negotiations with the U.S."

He added that mediators will convey the deadline set by Tehran to Washington and regional countries.

Washington did not immediately respond to the Iranian official's statements. However, Trump told Fox News on Monday that Iran "must raise the white flag of surrender."

He also threatened that if Oman obstructs the U.S. agreement with Tehran regarding the Strait of Hormuz, the U.S. will attack that country.