Sanders rebuts Biden on Clinton endorsement: 'We are not there at this moment'
Sen. Bernie Sanders (I-VT) speaks to 'All In' host Chris Hayes on June 30, 2016. (MSNBC)

Sen. Bernie Sanders (I-VT) confirmed on Thursday that he had spoken with Vice President Joe Biden -- but did not corroborate Biden's allegation regarding an endorsement of Hillary Clinton.

"I talked to Joe, I think it was three weeks ago," Sanders told MSNBC host Chris Hayes. "On that issue, we are trying to work with Secretary Clinton's campaign on areas that we can agree on."

NPR reported earlier in the evening that Vice President Joe Biden said the senator would indeed endorse Clinton as the Democratic presidential nominee in an interview taped for its Weekend Edition program.

Sanders reaffirmed that he would do everything he could to ensure the defeat of presumptive GOP nominee Donald Trump, but would not respond when Hayes pressed him on whether he saw himself eventually giving stump speeches on behalf of Clinton like Sen. Elizabeth Warren (D-MA) has done recently.

"We are working with the Clinton campaign, trying to be able to come forward and say to my supporters, 'Here's the progress that we have made,'" Sanders said, adding, "I hope that we can meet that goal. We are not there at this moment."

He also declined to go into detail on his recent meeting with President Barack Obama when Hayes alluded to a Washington Post report that Obama's administration had "leaned on key Democrats" to ensure that the party's platform would not include opposition to the Trans-Pacific Partnership, the multi-national trade deal Sanders has consistently criticized.

"On this issue we have a fundamental disagreement," the senator said.

Watch the interview, as aired on Thursday, below.