Carmen Roberts

This is Fox News.

Iran responds with its own ultimatum.

I'm Carmen Roberts, Fox News.

Iran says it will completely close the Strait of Hormuz if the U.S.

follows through with President Trump's threat to attack its power plants unless Iran opens the strait.

Last night, the president gave Iran just 48 hours to comply.

The president posted this warning, threatening to obliterate Iran's power plants within 48 hours from this exact time point.

Now, Trump posted that at 7.45 Eastern time last night, so the countdown continues to tick towards Monday night.

Now, the Strait of Hormuz supplies roughly one-fifth of the world's crude oil.

Now, the president has called NATO allies cowards for not sending warships to help defend the strait.

He claims because the U.S.

doesn't use the strait, this should be a global effort.

Now, this morning, the NATO Secretary General said countries support the U.S., but are still in the planning phase of sending help.

Fox's Dana Murray McNichol in West Palm Beach, Florida.

Iran is also threatening to retaliate directly by striking U.S.

and Israeli energy infrastructure in the region.

ICE agents will start showing up at U.S.

airports tomorrow as TSA struggles with a staffing shortage due to the DHS shutdown in funding.

And that's leaving travelers standing in very long security lines.

Transportation Secretary Sean Duffy on ABC's This Week.