Analysis: Trump's significant Iran statement still keeps everyone guessing
By Mark Stone, US correspondent in Washington
This is the most significant statement from the US president in days, though it still keeps everyone guessing.
In a message conveyed through his press secretary, he is giving diplomacy up to two weeks to work.
"Based on the fact that there's a substantial chance of negotiations that may or may not take place with Iran in the near future, I will make my decision whether or not to go within the next two weeks," Karoline Leavitt quoted him as saying.
Watch: Trump to make Iran decision 'in next two weeks'
It is not clear quite what "whether or not to go" entails. We know that he has been give a spectrum of different military options by his generals and we know that the Israelis are pressuring him to use American B2 bombers with their bunker busting bombs to destroy Iran's nuclear facility at Fodow.
The Israelis are encouraging no delay. But against that he is weighing up many risks both military and political.
Militarily it is not clear how successful a bunker busting strike on Fordow would be. Experts have suggested it would require several of the massive bombs, which have never been used in combat before, to be dropped on the site. It is not as simple as one clean strike and job done.
Politically, the president is under significant pressure domestically not to get involved in Iran.
Watch: MAGA civil war breaks out over Iran
Within his own MAGA coalition - influencers, politicians and media personalities are lining up in criticism of involvement in the conflict. One of those leading the criticism, his former chief strategist, Steve Bannon, who maintains huge influence, was seen entering the White House today.
His press secretary reiterated to us that the president always wants to give diplomacy a chance and she confirmed that his Middle East envoy Steve Witkoff has spoken to the Iranian Foreign Minister. European leaders including the UK foreign secretary, who is in Washington today, are meeting the Iranian Foreign Minister in Geneva tomorrow.
The two week window - assuming it lasts that long - also gives space to better prepare for any strike and mitigate against some of the other risks of US involvement. There are 40,000 troops in bases across the Middle East. It takes time to increase security at these bases or to move non-essential personnel out. It also takes time to move strategic military assets into the region.
The USS Nimitz aircraft carrier and its support vessels were redeployed from the Indo-Pacific on Monday. Their last known position was the Strait of Malacca two days ago. The Nimitz Carrier Group will overlap with the USS Carl Vinson group which was deployed to the Middle East in March.
The potential two week window also allows for more time for a "day after" plan given that the Israeli strategy appears to be regime change from within.
Since the Israeli action in Iran began last week, the worst case scenario of mass casualties in Israel from Iranian attacks has not materialised.
The president is said to be surprised and encouraged by this. "Israel has exceeded a lot of people's expectations in their abilities," press secretary Leavitt said.
The Israeli success, the absence of a mass casualty event in Israel and the lack of any sustained counter attack by Iranian proxies in the region removes reservations previous presidents have had about taking on Iran.