Never said when attack on Syria would take place: Trump

US President Donald Trump today asserted that he has never said when an attack, if at all, on Syria will take place, a day after he warned Damascus that US missiles "will be coming" in retaliation for an alleged chemical weapons attack on civilians in the strife-torn Arab country.

"Never said when an attack on Syria would take place. Could be very soon or not so soon at all!" Trump said amidst reports of an imminent American missile attack on Syria.

"In any event, the US, under my Administration, has done a great job of ridding the region of ISIS. Where is our 'Thank you America?'," he tweeted.

Two days ago, Trump had said that he would take a decision on Syria within 24-48 hours.

The White House yesterday said that the president is considering all options and no decision has been taken yet.

Former CIA Director and Defense Secretary Leon Panetta today told MSNBC that it was not something that the president should have said with regards to the status of American forces.

"Because if we're going to be able to have some kind of influence in Syria, and it is a chaotic situation, it is important for the United States to have a presence there and to indicate that we have a role to play," he said.

"By saying what he said, I think he may have sent a signal that somehow the United States would not care whatever happened in Syria, and I think that was dangerous," Panetta said.

The US, he rued, has really never had a strategy with regards to Syria.

"We've been reactive to the moment and to the crisis without thinking about what is our strategy in Syria, and as a result of that we've been somewhat ambivalent about how to handle that chaos," he said.

"And so, rather than developing that strategy, rather than trying to play a role in forcing Syria to figure out some kind of political settlement there that would get rid of Assad and allow Syrians to decide what their political future is, frankly, we have been hitting ISIS on the side talking about Assad but really don't have an overall strategy," Panetta said.

"If we're going to strike Syria I don't think this ought to be a reflex action without a strategy. That's what this administration has to do, is figure out what is our long-term strategy in Syria going to be," he said.