WASHINGTON (AP) — President Barack Obama is reassuring Italian Premier Matteo Renzi that Italy will remain one of the closest U.S. allies despite Renzi's defeat in a referendum on government-championed reforms.

Obama spoke to Renzi by phone on Tuesday. The White House says Obama thanked Renzi for his "close friendship and partnership" and that the two discussed the referendum. The vote was a humiliating defeat for Renzi, who has said he'll keep the promise he made to quit if the vote failed.

The call comes amid uncertainty about future U.S. relations with European allies under President-elect Donald Trump. The White House says Obama told Renzi that Italy will remain an "indispensable partner" due to their shared history and values.

The two leaders also discussed climate change, economics and the migrant crisis.