U.S. President-elect Donald Trump invited Philippine leader Rodrigo Duterte to the White House next year during a "very engaging, animated" phone conversation, a Duterte aide said on Friday, amid rocky relations between their two countries.

A statement issued by Trump's transition team, however, made no mention of an invitation.

Trump's brief chat with the firebrand Philippine president follows a period of uncertainty about one of Washington's most important Asian alliances, stoked by Duterte's hostility toward President Barack Obama and repeated threats to sever decades-old defense ties.