The White House on Thursday expressed its "unwavering" commitment to locate and return ex-FBI agent Robert Levinson, who disappeared 10 years ago on Iran's Kish Island.

"The Trump Administration remains unwavering in our commitment to locate Mr. Levinson and bring him home. We want him back, and we will spare no effort to achieve that goal," the White House said.

The former agent and ex-CIA contractor went missing in March 2007. His whereabouts has been yet another point of friction between Tehran and Washington.

Levinson was not part of the 2016 prisoner release deal that saw Washington Post journalist Jason Rezaian and four others released by Tehran.

President Barack Obama's White House had suggested that Levinson may no longer be in Iran.

The Trump White House has taken a more hardline stance against Tehran and on Thursday called for information and plugged a five million dollar reward for his "location and safe return."

"The Levinson family has suffered far too much during the last decade due to the absence of Mr. Levinson, a loving father, brother, husband, grandfather, and friend to many."

"Each and every day, but especially today, our hearts are with the Levinson family. We will not rest until this case is resolved."

source: AFP