The United States Senate has rejected a Republican bill to repeal the Affordable Health Care, popularly known as Obamacare which has been relentlessly criticised by President Donald Trump.

The bill which would have given a two-year window to bring a replacement of Obamacare was defeated by 55-45 votes yesterday in the Republican-majority Senate.

The House had earlier on Tuesday voted to start debate to replace the healthcare programme, signed into law by former President Barack Obama on March 23, 2010.

About 20 million Americans gained healthcare coverage under Obamacare, but Republicans viewed it as an overreach of the federal government and said patients had less choice and higher premiums.

On Wednesday, seven Republicans, including Senator John McCain, voted no to the move to only repeal Obamacare and giving a two-year window for a new healthcare bill for its replacement.

“I have said consistently that I support repealing and replacing Obamacare, and I voted to do so last night. I'm not giving up on doing both of those things,” Ohio Senator Rob Portman said.

“We need to roll up our sleeves and come up with a better healthcare system. Just kicking the can down the road adds more uncertainty to the failed status quo,” he said.

Portman was one of the seven Republican senators who voted against the repeal-only Obamacare bill.

Speaking on the Senate floor, Senator Rand Paul said one has to start somewhere.

“We have to start somewhere. And where we should start is where we all promised we would be here to repeal Obamacare, he argued in favor of the bill.

“We all ran on it. All but one of us voted for it in 2015. It is simple. If you are against the taxes and mandates of Obamacare you have an obligation to vote for this bill,” he said.

Paul said being a doctor he has seen the “disaster that is Obamacare up close”.

Senate Majority Leader Mitch McConnell said even though the proposal failed, it represented a number of important healthcare reform ideas developed by lawmakers.

“We'll consider many different proposals throughout this process from senators on both sides of the aisle. Ultimately, we want to get legislation to finally end the failed Obamacare status quo through Congress and to the president's desk for his signature,” he said.