The U.S. House of Representatives will send its healthcare overhaul plan passed earlier this month to the Senate in a couple of weeks after it receives a final analysis by congressional reviewers, U.S. House Speaker Paul Ryan said on Friday.

Ryan said in a radio interview that the delay was "out of an abundance of caution" until the Congressional Budget Office (CBO) releases its findings on the legislation's costs and its impact on health insurance coverage.

The CBO's analysis, or "score," is expected late Wednesday, taking into account final changes to the bill before it passed the Republican-led House earlier this month.

"We are just basically being overly cautious, but there's really kind of a non-issue here. We’re moving it over to the Senate probably in a couple of weeks.” he added

Republicans are eager to make good on their campaign promise to repeal and replace the 2010 Affordable Care Act, Democratic former President Barack Obama's signature healthcare law, also known as Obamacare.

Public opinion polls have shown slipping support for Republican efforts. A Politico/Morning Consult poll this month found 44 percent of nearly 2,000 people surveyed disapproved of the House bill compared with 38 percent who approved of it.

House Democratic Leader Nancy Pelosi's spokesman, Drew Hammill, said the House bill was becoming a liability for Republicans and "has no chance of success in the Senate, and now may even have to come back to the House to be amended."

Before the latest changes, the CBO had said the bill would leave 24 million more Americans uninsured by 2026 and slice about US$150 billion off the budget deficit.