The U.S.-Israeli campaign against Iran is in its fourth week....

White House press secretary Karoline Leavitt said on Wednesday that Donald Trump would intensify military action against Iran if Tehran refuses to accept what she described as its military defeat.

“President Trump does not bluff and he is prepared to unleash hell. Iran should not miscalculate again,” Leavitt told reporters at a White House briefing.

“If Iran fails to accept the reality of the current moment, if they fail to understand that they have been defeated militarily, and will continue to be, President Trump will ensure they are hit harder than they have ever been hit before,” she said.

As the joint U.S.-Israeli campaign against Iran entered its fourth week, countries including Pakistan, Turkey and Egypt have stepped up mediation efforts.

A senior Iranian official said Tehran was still reviewing a U.S. proposal to end the conflict despite an initially negative response, stopping short of rejecting it outright.

Leavitt said talks with Iran were ongoing and described them as productive.

“Talks continue. They are productive, as the president said on Monday, and they continue to be,” she said.

Media reports citing unnamed sources said Washington had sent Tehran a 15-point plan to end the war. Leavitt said elements of the reports were inaccurate but did not elaborate.

“The White House never confirmed that full plan. There are elements of truth to it, but some of the stories I read were not entirely factual, so I am not going to negotiate on behalf of the president here at the podium,” she said.

Global equity markets rose and oil prices dipped on Wednesday following the reports, as investors hoped for an end to a conflict that has disrupted energy supplies and fuelled inflation concerns.