Florida's Republican Governor Ron DeSantis has signed a bill banning most abortions after six weeks, paving the way for drastic changes in access to the procedure across the state.

Opponents argue six weeks is before many women know they are pregnant.

The law will not go into effect until a court rules on an ongoing legal challenge to the existing 15-week ban.

"We are proud to support life and family in the state of Florida," the governor said in a statement.

He claimed the law would "defend the dignity of human life and transform Florida into a pro-family state".

The state has been a safe haven for those seeking abortion in the country's south-east since Roe v Wade - which gave women in the US the constitutional right to abortion - was overturned last year.

The state's current 15-week limit on abortion is one of the most lenient in the south-east, with many travelling from other states to Florida to have the procedure.

The six-week ban makes exceptions for abortions in cases of rape or incest, as long as the woman can provide documentation such as a police report or a restraining order.

Mr DeSantis' signed the bill late Thursday night just hours after Florida's Republican-led House of Representatives approved the ban on Thursday, with 70 voting for and 40 voting against. It had been passed in the state Senate on 3 April.

"A woman's right to choose, I've heard people talk about that," Republican lawmaker Kiyan Michael said during the debate, as quoted by CNN. "Well, that right to choose begins before you have sex."

In a statement shortly after Mr DeSantis signed the bill, the Florida Alliance of Planned Parenthood Affiliates said the ban's exceptions for rape or incest would not provide "meaningful access to patients in need".

The group argued the bill as a whole would "shut down a critical abortion access point for millions across the southeast, Caribbean, and Central and South America".

The fate of the new six-week abortion law is still contingent upon another ruling from Florida's Supreme Court.

Florida's highest court is hearing a challenge brought by abortion clinics to the state's existing 15-week ban. The latest law signed by Mr DeSantis contains language that says the six-week ban would only go into effect if Florida's highest court upholds the 15-week law that is already in place.

Florida's conservative Supreme Court is expected to side with anti-abortion activists and rule the 15-week ban is constitutional.

National debate over abortion in the US has been raging since a federal judge suspended the original approval of a widely used abortion drug, mifepristone, last week.

That suspension was later blocked by an appellate court, and the Biden administration has said it will ask the Supreme Court to restore full access to the drug.