Washington, July 2 -- US Vice President JD Vance said negotiations with Iran in Doha are progressing positively but warned that military action remains an option if Tehran fails to meet Washington's expectations.

Speaking to reporters after addressing Marines at Naval Air Station Oceana in Virginia, Vance said President Donald Trump remained committed to pursuing diplomacy but would not hesitate to act if Iran resumed activities viewed as being threatening to Washington.

"I can't commit to anything, because obviously it depends on what the Iranians are ultimately going to do," Vance said.

"What I can commit to is the president's not going to send our military back in unless he has to, unless there's a clearly defined purpose for it."Vanc...