How he responds to Iran could be a decisive moment in his presidency.

President Donald Trump is set to address the nation at 11 a.m. Wednesday morning from the White House following an attack by Iran overnight on two bases in Iraq where U.S. troops are stationed.

The president announced the planned address in a tweet Tuesday night, reacting to Iran’s strike on two facilities in Iraq in an upbeat tone as initial assessments showed there had been no U.S. causalities as a result of the retaliatory attack.

“All is well! Missiles launched from Iran at two military bases located in Iraq. Assessment of casualties & damages taking place now. So far, so good! We have the most powerful and well equipped military anywhere in the world, by far! I will be making a statement tomorrow morning,” Trump tweeted.

The president’s tweet represented a departure from his tougher rhetoric earlier in the day, when he warned “If Iran does anything that they shouldn’t be doing, they’re going to be suffering the consequences and very strongly.”

Iran launched the attack in retaliation of the U.S.-ordered killing of top Iranian commander Qassem Soleimani last week. President Trump and the broader administration have said Soleimani was working to orchestrate an “imminent” attack targeting U.S. personnel and facilities in justifying the killing, though Democrats have been raising questions about what evidence the administration has that an attack was indeed “imminent” and the administration has so far refused to declassify that intelligence.

The White House has not offered any guidance about what the president’s message will be but have said he will make the address from the White House’s Grand Foyer.

The address comes at perhaps a pivotal moment for Trump, who was elected to the White House three years ago on a promise to untangle the US from endless wars in the Middle East. But on the dawn of an election year, the president’s killing of Soleimani has brought the US closer to the brink of expanded military conflict in the region.

The choice before the president in making his next move could be critical in setting the nation on the path toward all-out war with Iran or alternatively could dial back the tension by stepping back from a tit-for-tat posture.