The White House is planning for a potential summit between President Donald Trump and President Vladimir Putin of Russia, according to people familiar with the efforts, a meeting that would bring to the international stage one of the world's most enigmatic political relationships.

A senior administration official said Friday that Jon Huntsman, the U.S. ambassador to Russia, has been in Washington to help arrange a meeting between Messrs. Trump and Putin.

The planning is still at an early stage, the official said, with the two nations needing to agree on a date and location.

"This has been an ongoing project of Ambassador Huntsman, stretching back months, of getting a formal meeting between Putin and Trump," the official said.