Secretary of State Antony Blinken said Tuesday that efforts to bring home Americans wrongfully detained in Iran are not linked to efforts to rein in Tehran’s nuclear activity.

The secretary added that Iran’s positive steps toward freeing the imprisoned Americans do not impact the Biden administration’s objections to the Islamic Republic’s other abusive actions, including its human rights violations; support for terrorist proxies in the Middle East and attacks against U.S. troops in the region; and providing weapons to Russia for use in Ukraine.

“Nothing about our overall approach to Iran has changed,” Blinken said in a press conference at the State Department. 

“We’ve been clear that Iran must de-escalate to create space for future diplomacy. This development, that is the move of our detainees out of prison and to home detention, is not linked to any other aspect of our Iran policy, it is simply about our people.” 

The Biden administration announced last week that five Americans imprisoned in Iran were released and placed on house arrest as part of negotiations toward their eventual return to the U.S.

U.S. officials have cautioned that talks with Iran to free the Americans remain ongoing. Part of the negotiations with Iran is allowing Tehran to access $6 billion in oil profits frozen in a South Korean bank, which the administrations says can only be used for humanitarian purposes.

The release of the Americans is also reportedly contingent on an exchange of Iranians jailed in the U.S. on charges related to sanctions violations. 

Blinken said negotiations to secure the Americans’ release have always been separate from the administration’s pursuit of diplomacy with Iran to roll back advancements to its nuclear weapons program. Iran began pursuing those advancements following former President Trump’s withdrawal from the Joint Comprehensive Plan of Action (JCPOA), the formal name for the nuclear deal that put strict caps on Iran’s nuclear activity in exchange for sanctions relief.

Intensive diplomacy by the Biden administration and the European signatories to the JCPOA to rejoin the nuclear deal fell apart over Iranian demands that the U.S. said were unrelated to the deal. The talks between U.S. and Iranian officials — conducted through intermediaries — further fell apart over criticisms of Iran’s brutal crackdown on domestic protests related to the death in Iranian custody of a young Iranian woman, Mahsa Amini, who was detained for allegedly wearing her headscarf inappropriately.

But the Biden administration in recent weeks had reportedly engaged with Iran over efforts to de-escalate its nuclear activity and roll back its enrichment of nuclear weapons-grade fuel to 60 percent purity, below the 90 percent needed for a bomb but far above the 3.67 percent limit of the JCPOA.

Blinken on Tuesday would not confirm a Wall Street Journal report that Iran had slowed its buildup of weapons-grade uranium as part of easing tensions linked to the efforts to return home-detained Americans, free up Iran’s oil profits for humanitarian purposes and release Iranians in U.S. jails.

“There is no agreement between us on nuclear matters,” he said.

“The agreement that we’re pursuing to bring home those who are wrongfully detained in Iran is an entirely separate matter that we want to bring to a successful conclusion. And that’s what I’m focused on.”

Blinken also wouldn’t address the imprisonment in Iran since 2016 of U.S. permanent resident Shahab Dalili, whose family argues he is being unjustly detained, though the Biden administration has yet to make such a determination.

Dalili is reportedly on hunger strike in jail, while his son Darian is carrying out a hunger strike in the U.S. while protesting in Washington.

“We continue to look, and will always continue to look at the situation’s conditions of other Americans around the world, who may be detained,” Blinken said. He added that he was barred from talking about individual cases because of privacy reasons.

“I can simply say that as a matter of policy we’re constantly reviewing whether any particular individual, whether an American citizen or legal permanent resident, who is incarcerated in another country is wrongfully detained, and that of course triggers a whole series of actions and steps that we take to try and secure their release.”