WASHINGTON Secretary of State John Kerry said on Friday he raised the topic of detained Americans at every meeting he held with Iranians during the final weeks of nuclear negotiations and said he is hopeful Tehran would release them.
The Obama administration has faced criticism for not securing the Americans' release as part of the landmark deal reached on Tuesday in Vienna to curb Iran's nuclear program in exchange for sanctions relief.
There are three Americans known to be detained by Iran.
In an interview with MSNBC's "Morning Joe," Kerry defended his team's efforts to get them freed, including during the final round of negotiations that began on June 27.
"There was not a meeting that took place - not one meeting that took place, believe me that's not an exaggeration - where we did not raise the issue of our American citizens being held," he said.
Kerry said he brought it up with Iranian Foreign Minister Jawad Zarif just before the two went out to announce the deal.
"We remain very, very hopeful that Iran will make the decision to do the right thing and to return those citizens to the United States," Kerry said in the MSNBC interview. "And we are consistently, constantly even now continuing to work on that."
The Americans known to be held in Iran include Washington Post correspondent Jason Rezaian, who is being tried on espionage charges after his arrest in July 2014.
U.S. President Barack Obama in March urged Iran's government to release Rezaian and two other detained Americans - Saeed Abedini and Amir Hekmati - and to help find Robert Levinson, an American who disappeared in Iran eight years ago.