AP
Donald Trump.
"I can tell you this: I would," the presidential candidate said when asked by conservative radio host Hugh Hewitt whether he supports shutting the government down in the fight.
"I think you have to in this case," added Trump, the current front-runner in Republican primary polls.
Congressional Republicans and Democrats, along with President Barack Obama, are heading for another standoff in September that revolves around funding for the health and family-planning organization.
The organization has come under intense scrutiny after the release of undercover videos that show Planned Parenthood executives discussing using aborted fetuses for research. The conservative group that released the videos says they show the executives discussing the sale of body parts of aborted fetuses.
However, Planned Parenthood claims the videos were selectively edited. Democrats have rallied to its defense, saying the nonprofit supports a wide swath of important women's health needs.
The government could shut down on October 1 if Congress does not pass a bill that keeps the government funded. And Republicans are already starting to signal that they won't support a spending bill that includes funding for Planned Parenthood, which receives more than $500 million in taxpayer money each year.
In the Senate, social conservatives are leading a push to attach a rider to the spending bill that would eliminate the funding. In a vote that's expected to be a precursor for September's fight, Senate Democrats filibustered legislation cosponsored by presidential candidate and Sen. Rand Paul (R-Kentucky) that would have halted the funding.
And in the House, 18 conservatives have also told House Republican leadership that they will not support a bill to fund the government if it includes funding for Planned Parenthood.
In his Monday interview, Trump said Republicans should remain united the battle over Planned Parenthood. The real-estate developer contrasted the current debate with what he said were mistakes during the last federal-government shutdown in 2013 over the Affordable Care Act.
"I was also in support - if the Republicans stuck together, you could've done it with Obamacare, also," Trump said. "The Republicans decided not to stick together, and they left a few people out there, like Ted Cruz. They left a lot of the people that really went in and wanted to do the job. And you know what? If they stuck together, they would've won that battle.