US President Donald Trump has broken his Twitter silence over his failed initiative to repeal and replace Obamacare.

A vote on the Republican's healthcare plan was cancelled by the House yesterday (24 March) after it became clear he had not secured enough votes to see the legislation pass.

And the president has made it clear he isn't happy following the embarrassing setback.

Taking to Twitter, Trump wrote: "ObamaCare will explode and we will all get together and piece together a great healthcare plan for THE PEOPLE. Do not worry!"

Despite Trump's threat to the GOP that a failure to vote in favour of his healthcare bill would mean Obamacare remained in place, the president clearly hopes for an opportunity to dismantle the Affordable Care Act in future, as per his campaign promise.

Following the cancelled vote, Trump laid the blame at the feet of Democrats, stating it was hard to do anything without their support – despite the fact the GOP has control of the House and the Senate.

"We learned a lot about loyalty," said Trump. "We learned a lot about the vote-getting process. We were just probably anywhere from 10 to 15 votes short," he added. "With no Democrat support we couldn't quite get there."

It is believed Trump was at least 25 votes short, with several members of the conservative House Freedom Caucus refusing to back the healthcare bill.

White House press secretary Sean Spicer told The Wall Street Journal of the failure to get backing for the bill. "Part of it is trying to figure out as you go down this path who you can rely on and who's going to keep your word.

"Who's going to negotiate in good faith? We dealt with over 120 members of Congress and you learn a little about some of these individuals ... you just learn a lot about who you can count on and who you can't," he added.