"ObamaCare will explode and we will all get together and piece together a great healthcare plan for THE PEOPLE. Do not worry!" the Republican said on Twitter.
The message came one day after the president suffered the biggest defeat yet in his short White House tenure, when his bill to repeal Obamacare died at the hands of rebel lawmakers of his own Republican party.
Trump and House Speaker Paul Ryan were forced to withdraw the legislation moments before a vote, having failed to round up enough support for passage -- leaving the president's campaign pledge to dismantle his predecessor's health care reforms unfulfilled.
The real estate mogul-turned-politician -- who built his candidacy on his bona fides as a skilled negotiator -- had thrown his full political weight behind the measure and helped twist the arms of recalcitrant Republicans to rally votes.
He declared himself "disappointed" and a "little surprised" by the defeat of the bill, which in addition to opposition by several factions of Republicans was totally shunned by Democrats.
"Bad things are going to happen to Obamacare. There is not much you can do to help. I've said that a year and a half. Eventually it's not sustainable," Trump said after the bill was withdrawn.
But he indicated the divisive issue will remain on the White House agenda.
"I think we have to let Obamacare go its way... It's imploding and soon will explode and it's not going to be pretty," he said.