WASHINGTON Joe Biden's administration did not sanction secret meetings that former top U.S. national security officials held with Russian Foreign Minister Sergei Lavrov and other Russians on potential talks to end the Ukraine war, a State Department spokesperson said on Thursday.

NBC News reported that the former U.S. officials met Lavrov in New York in April, joined by Richard Haass, a former U.S. diplomat and outgoing president of the Council on Foreign Relations, and two former White House aides.

It was not clear how frequently the group, which included former Pentagon officials, held discussions with other prominent Russians thought to be close to the Kremlin, NBC News reported. At least one unidentified group member traveled to Russia, it said.

"The Biden administration did not sanction those discussions," the State Department spokesperson said in response to questions from Reuters. "And as we've said repeatedly, nothing about Ukraine without Ukraine."

The spokesperson was referring to an administration policy of not discussing possible negotiations on ending the war without involving Ukrainian officials.

The administration, the spokesperson said, would continue providing weaponry to Kyiv so that Ukrainian officials "can negotiate from a position of strength when they think the time is right."

NBC News, quoting six people briefed on the discussions, said they were aimed at laying the groundwork for possible talks on ending the war that erupted with Russia's full-scale invasion of Ukraine in February 2022.

It quoted two sources as saying that the discussions took place with the administration's knowledge but not at its direction and that those who met Lavrov briefed the White House afterwards.

(Reporting by Jonathan Landay and Simon Lewis)