GEOFF BENNETT: Welcome to the "News Hour."

President Trump said today he was unhappy with the progress of diplomacy with Iran and suggested he may, as he put it, have to use the military.

That came in contrast to a statement from the mediator of the talks, who said they're making progress.

And's as the U.S.

has deployed the largest military presence in the Middle East in more than two decades.

Here's Nick Schifrin.

NICK SCHIFRIN: Today, as the U.S.

prepares for the prospect of war, President Trump did not hide his disappointment in U.S.-Iran nuclear talks.

DONALD TRUMP, President of the United States: We're not happy with the negotiation.

They just don't want to -- they don't want to say the key words, we're not going to have a nuclear weapon.

They have to say, we're not going to have a nuclear weapon.

And they just can't quite get there.

NICK SCHIFRIN: And President Trump stuck to his demand that Iran not be allowed to create any nuclear fuel.

DONALD TRUMP: They want to enrich a little bit.

You don't have to enrich when you have that much oil.

So, I'm not happy with the negotiation.

NICK SCHIFRIN: The man in the middle of that negotiation, mediating between Americans and Iranians, has been Omani Foreign Minister Badr bin Hamad Al Busaidi.

Today, he met with Vice President J.D.

Vance and other U.S.

officials and afterward told CBS' Margaret Brennan the talks were making progress.

BADR BIN HAMAD AL BUSAIDI, Omani Foreign Minister: So there would be zero accumulation, zero stockpiling, and full verification.

NICK SCHIFRIN: That suggests Iran has agreed not to store any nuclear fuel, but not necessarily to stop enriching entirely.

Al Busaidi also said that, for the first time, Iran would agree to Americans verifying Iran's nuclear program.

BADR BIN HAMAD AL BUSAIDI: If I was President Trump, my only advice is just to give those negotiators enough room and enough space to really close these remaining areas that we need to discuss and agree upon.

MARGARET BRENNAN, Host, "Face the Nation": And if Israel carries out a strike, or if the U.S.

carries out even a limited strike on the ballistic missiles, do you think that you could still get a nuclear deal done?

BADR BIN HAMAD AL BUSAIDI: Well, diplomacy can reach a deal.

I don't think any other acts can solve this problem, really.

NICK SCHIFRIN: But the momentum appears to be toward a strike.

White House senior adviser Dan Scavino posted on social media a row of B-2 bombers, the same plane used in last summer's Iran strikes.

And, overnight, also precautions for possible war.

The U.S.

Embassy in Israel told its staff to consider leaving the country immediately.

U.S.

Ambassador Mike Huckabee wrote an internal e-mail obtained by the Associated Press that said there was no need for panic, but -- quote -- "Those wishing to take authorized departure should do so TODAY," "today" written in capital letters.

And the U.S.

official confirms to "PBS News Hour" the military's top Middle East commander, Admiral Brad Cooper, briefed President Trump yesterday on options for a strike.

There are negotiations scheduled for next week after yesterday's meeting in Geneva.

Iran says technical talks are supposed to begin Monday.

But the U.S.

has assembled what President Trump has called an armada, the largest deployment of warships and aircraft in the Middle East in decades.

And despite the mediator claiming progress, the U.S.

has set the theater for an attack.

For the "PBS News Hour," I'm Nick Schifrin.