"No deal," House Freedom Caucus Chairman Mark Meadows said after he and his group of more than two dozen conservatives met Trump on Thursday to try to get more concessions to reduce requirements on insurance companies.

Repealing and replacing former president Barack Obama's healthcare law was one of the major campaign promises of Trump, who ran as a master dealmaker.

The legislation drafted to replace it has come under attack from both conservative and moderate Republican lawmakers, leaving it short of votes. Democrats are unified in their opposition to the bill.

A senior White House official told Reuters news agency that Thursday's vote was delayed so it would not be held in the middle of the night. The official said the vote will be held on Friday morning.

The Republican legislation would halt Obama's tax penalties against people who do not buy coverage and cut the federal-state Medicaid programme for low earners, which the Obama statute had expanded.

It would provide tax credits to help people pay medical bills, though generally skimpier than Obama's statute provides.

It also would allow insurers to charge older Americans more and repeal tax boosts the law imposed on high-income people and health industry companies.

The measure would also block federal payments to Planned Parenthood for a year, another stumbling block for Republican moderates.

- News24.com