 -- Former Vice President and climate advocate Al Gore met with Donald Trump at Trump Tower in New York City today.

Gore said he had a "lengthy and very productive session" with the president-elect, who has previously called climate change a "hoax."

"I found it an extremely interesting conversation and to be continued and I’m just going to leave it at that," Gore told reporters of the meeting with the president-elect. "It was a sincere search for areas of common ground."

Gore also met with Trump’s daughter Ivanka Trump.

The meetings with the two Trumps came against the backdrop of the future first daughter also recently meeting with actor Leonardo DiCaprio, an outspoken advocate on climate change issue. A source with knowledge of the meeting told ABC News that DiCaprio gave Ivanka Trump a copy of his documentary “Before the Flood.” The DiCaprio meeting was first reported by The New York Times.

Politico has also reported that Ivanka Trump intends to make climate change one of her “signature issues” with her father in the White House. The transition team has yet to specify what role the future first daughter may play in a Trump administration but has referred to her as an adviser to the transition.

While the specifics of Ivanka Trump’s views on the issue of climate change are not publicly known, the Trump transition made clear as recently as Friday that the future administration will take a different approach to the issue than the Obama administration has.

On Friday, a leaked internal memo said that the president-elect supports the completion of the Dakota Access oil pipeline, which the Army Corps of Engineers on Sunday blocked from running through a disputed piece of land. Native Americans and environmental advocates say the pipeline threatens sacred sites and a local water supply.

Still, Trump has indicated a willingness to moderate his previous positions on climate change since winning the election. While he vowed to "cancel" the Paris climate agreement while on the campaign trail, he told the New York Times recently that he is looking at the accord "very closely" and has an "open mind."

ABC News' Arlette Saenz contributed to this report.