NASHVILLE (AP) — Tennessee Gov. Bill Lee says he wants to enact some of the strictest abortion laws in the nation, which would include banning women from undergoing the procedure once a fetal heartbeat is detected.

The Republican governor made the announcement Thursday surrounded by dozens of mostly male GOP state lawmakers — many of whom are up for reelection later this year.

"We're taking a monumental step forward in celebrating, cherishing and defending life," Lee said. "I'm proud to be joined by members of the General Assembly who have helped lead the way in this important effort."

Lee said he will soon introduce legislation that will ban abortions once a fetal heartbeat is detected — about six weeks into pregnancy, before many women know they're pregnant. Similar legislation has been enacted in other states, such as Mississippi and Georgia, but has been blocked by legal challenges.

Those court cases are expected to take years to snake their way through the legal system.

Supporters of the bills want to bring these types of lawsuits to an increasingly conservative U.S. Supreme Court in hopes of ending the constitutional right to abortion protected under the 1973 Roe v. Wade landmark ruling.

"You can't overturn Roe v. Wade without challenging the constitutionality of it," Sen. Mike Bell, a Riceville Republican, told reporters. "We know that this is going to be challenged. We know it's pushing the envelope. It has to."

Last year, a similarly proposed heartbeat ban failed in Tennessee. Lee came out in support of the idea early in his first year as governor, but key abortion foes inside the GOP-dominant Statehouse were wary. They pointed to multiple courts striking down prior abortion restrictions in other states.

Senate Speaker Randy McNally was among those who worried last year about the courts' response to the tighter restrictions, saying at the time that it was best "not try to do everything at once, but sort of move ahead with some caution."

As of Thursday though, McNally said he believes the governor's anti-abortion proposal will be more legally sound than the one introduced in 2019 because of provisions that are expected to be in this version.

"I believe it will have what's called the ladder provision in it, that if the heartbeat gets struck down, then there would be a ban at eight weeks and then 10 weeks and on up," McNally said.

Doing so, McNally said will mean "the bill will survive."

Exceptions for rape and incest in Lee's proposal are not expected to be included, McNally said.

Meanwhile, House Speaker Cameron Sexton touted Republican efforts to limit abortion in Tennessee, but held off from directly endorsing Lee's proposal.

"We are looking forward to working with (Lee) and his team on this issue, as well as his legislative vision," he said in a statement. "I know members of the House and the chairmen are eager to review the proposed language and continue their strong support for life."

Additionally, Lee said he also intends to ban abortion for women seeking to end their pregnancies because of the gender, race or disability of the fetus. Finally, Lee said he wants to require women seeking an abortion to be shown an ultrasound of the fetus before they can receive the procedure.

Specific details about the proposals, however, remain largely unknown. Lee unveiled his plans while acknowledging the anti-abortion proposals were still being drafted and had not yet been finalized.

Lee's announcement sparked immediate opposition from Democrats and abortion rights supporters.

The proposal would be "blatantly unconstitutional," said Francie Hunt, executive director of Tennessee Advocates for Planned Parenthood.

"I'm so blown away by the intent behind it, which is basically a power grab over our bodies," Hunt said.

Meanwhile, Democratic lawmakers pointed out that Republicans have long refused to support initiatives that would improve pregnant women's lives while proclaiming to be focused on "protecting life."

Expanding Medicaid eligibility, refusing to ban shackling of pregnant inmates during and after childbirth, and adding paid parental leave have all recently been rejected by Republican lawmakers.