Republican presidential running mate Sen. JD Vance offered few specifics when grilled Friday about how former President Donald Trump would pay for his new plan to require the government or private insurers to cover the cost of in vitro fertilization treatments.

"Is this an expansion of Obamacare? Is this a mandate?" CNN anchor John Berman asked the Ohio senator.

"Well, look, I think you have insurance companies that obviously are forced to cover a whole host of services," Vance replied.

"The President explicitly said that he wants insurers to cover additional fertility treatment," he added, blaming Democratic presidential nominee Kamala Harris for high consumer costs more broadly.

Trump had unveiled the IVF policy in broad strokes during a campaign event in Michigan a day earlier.

"I'm announcing today in a major statement that under the Trump administration, your government will pay for — or your insurance company will be mandated to pay for — all costs associated with IVF treatment," he said.

He later told NBC News that a future Trump administration will be "paying for that treatment," while also adding, "We're going to be mandating that the insurance company pay."

IVF is used in the overwhelming majority of assisted reproductive procedures in cases of infertility. But it can be prohibitively expensive, ranging from $15,000 to more than $30,000 for a single IVF cycle, and it takes an average 2.5 cycles to become pregnant, according to the U.S. Department of Health and Human Services.

The Society for Assisted Reproductive Technology said nearly 390,000 IVF cycles were performed at its 368 member clinics in 2022, a 6% increase from the prior year.

Based on an average initial cost of $20,000 per round of IVF, either taxpayers or private insurers would be on the hook for an annual bill of nearly $8 billion under Trump's plan.

Moreover, if IVF treatments were offered with no out-of-pocket expenses, the same way routine checkups and mammograms are under the Affordable Care Act, there would likely be a surge in the number of patients seeking the treatment.

Trump's embrace of IVF as a policy platform is the former president's latest effort to court voters concerned about women's reproductive rights.

Recent polls of the presidential race show Harris with a substantial lead over Trump among women voters.

The lead reflects a broader shift underway in the electorate since the Supreme Court overturned Roe v. Wade in 2022, which had protected federal abortion rights for nearly 50 years.

The majority bloc in the case, Dobbs v. Jackson Women's Health Organization, included three conservative justices whom Trump had nominated to the bench.

In the two years since the Dobbs decision, 22 states have enacted either blanket bans on abortion or restrictions that go further than the prior standard did under Roe, according to The New York Times.

Trump has repeatedly taken credit for ending Roe, while falsely claiming that experts of all political stripes unanimously wanted the abortion issue to be decided by individual states, rather than by the federal government.

While he has courted anti-abortion voters and advocacy groups during his third run for president, Trump has also sought to distance himself from states that have subsequently moved to strengthen restrictions on abortion in the wake of Dobbs.

He has also come out against the proposals by some of his GOP allies, including Sen. Lindsey Graham of South Carolina, for a federal abortion ban. The Republican Party in July adopted a new Trump-backed platform that significantly softened its stance on abortion.

The Harris campaign has nevertheless repeatedly warned that Trump would impose a nationwide abortion ban if he wins a second term in the White House.

IVF came to the forefront of the clash over reproductive rights in February, when an Alabama Supreme Court ruling spurred fertility treatment providers in the state to pause their services for fear of legal exposure.

Democrats quickly linked the development to Trump and Dobbs. Trump, in turn, urged the state to find a solution that would "preserve the availability of IVF in Alabama."

In Friday's CNN interview, Vance was asked how Trump's new federally mandated IVF funding plan would work if a state chose to ban the procedure.

Vance responded, "I think it's such a ridiculous hypothetical," adding that Alabama "has actively protected fertility access and fertility treatment."

Alabama Gov. Kay Ivey signed a state law in early March aiming to protect IVF and stamp out the controversy over the court ruling. But multiple IVF clinics in the state have closed in the wake of the controversy.

Vance also faced repeated questions about Trump's recent remarks on a hotly contested ballot measure that would extend abortion rights in Florida up to the point of fetal viability, which is generally around the 24th week of pregnancy.

If it passes, the ballot initiative known as Amendment 4 would override a bill signed into law last year by Republican Gov. Ron DeSantis, which banned most abortions in Florida after six weeks of pregnancy — a stage at which many women do not yet know they are pregnant.

"I am going to be voting that we need more than six weeks" of access to legalized abortions, Trump told NBC's Dasha Burns on Thursday.

Trump's answer drew fierce condemnation from high profile anti-abortion advocates.

"Voting for FL Amendment 4 is a vote for China and Harris no limits abortion policy," said Marjorie Dannenfelser, president of the national anti-abortion group SBA Pro-Life America, on social media site X.

"This would leave no contrast" between Trump and Harris, she wrote, tagging Trump's social media account.

Facing a firestorm of criticism from the anti-abortion right, Trump's presidential campaign sought to walk back his comments and leave some ambiguity as to how he would vote on Amendment 4.

"President Trump has not yet said how he will vote on the ballot initiative in Florida, he simply reiterated that he believes six weeks is too short," the campaign said in a statement.

On Friday, Vance insisted to CNN that Trump's position on abortion has been "extremely consistent." But he also emphasized that Trump has not yet made up his mind about Amendment 4.