WASHINGTON — The Biden administration on Thursday imposed sanctions on the F.S.B., Russia’s intelligence agency, for its role in detaining Americans like Evan Gershkovich, the Wall Street Journal reporter who has been accused of espionage.
The administration also announced sanctions on Iran’s intelligence services and four senior Iranian officials, who the administration says have participated in a pattern of holding Americans and other nationals hostage.
The actions are the first attempt by the U.S. government to formally punish foreign governments for taking Americans by seeking to cut off access to the international financial system. In a statement on Thursday afternoon, President Biden urged both countries to let their hostages go.
“Today — and every day — our message to Russia, Iran and the world is holding hostage or wrongfully detaining Americans is unacceptable,” Mr. Biden said. “Release them immediately.”
He said that the sanctions meant that “all of the designees’ property and interests in property in the possession or control of U.S. persons are now blocked.”
But administration officials acknowledged that the sanctions were designed primarily as a way to send a message of disapproval to Russia and Iran, as both countries’ intelligence agencies had already been subject to stiff financial sanctions for actions in other areas.
Still, the officials, who requested anonymity to discuss the sanctions before they were officially announced, said imposing the punishments on the two regimes was an important part of the often difficult effort to bring Americans home.
They hinted that the sanctions could become a bargaining chip in future negotiations over the release of Mr. Gershkovich or other detained Americans. When asked whether lifting the sanctions could be part of negotiations, one official pointed to language in an official announcement by the Treasury Department’s Office of Foreign Assets Control.
“The power and integrity of O.F.A.C. sanctions derive not only from O.F.A.C.’s ability to designate and add persons” to the sanctions list, the Treasury announcement says, “but also from its willingness to remove persons.”
“The ultimate goal of sanctions is not to punish,” the statement adds, “but to bring about a positive change in behavior.”
It is unclear, however, how much weight the intelligence agencies in Russia and Iran would give to the imposition of the sanctions, or the prospect of eventually getting them lifted.
If the F.S.B. or the intelligence arm of Iran’s Revolutionary Guard had financial assets in foreign countries at some point, those assets were likely frozen or cut off long ago, due to sanctions related to Russia’s invasion of Ukraine or Iran’s pursuit of nuclear weapons.
In addition to the two agencies, four Iranian officials were targeted for sanctions. They include the commander of the Iranian Revolutionary Guard intelligence agency, two deputies, and a counterintelligence official at the agency. Officials said all four men have been involved in wrongfully detaining Americans and other activities, including assassination plots.
The officials said they anticipated other sanctions would be imposed for hostage taking in the coming months.
Mr. Gershkovich was the latest American to be held by Russia when he was detained on March 30 and accused of espionage. The Biden administration has said Mr. Gershkovich is not a spy and has designated him as wrongly detained by Russia.
After talking with Mr. Gershkovich’s family days after he was detained, Mr. Biden said his administration was “making it real clear that it’s totally illegal what’s happening.”
Officials said that the decision to prepare sanctions on Russia and Iran began long before Mr. Gershkovich was detained by Russia, but added that his case added to the “pattern of activity” that justified punishing the government.
In addition to Mr. Gershkovich, Russia is still holding other Americans, including Paul Whelan, a former U.S. Marine who has been held in Russia since 2018 on what the U.S. government says are fabricated espionage charges. Russia is also holding Marc Fogel, an American who was sentenced to 14 years in a penal colony for possessing a small amount of medical marijuana.
Brittney Griner, an American basketball star detained on similar drug charges, was released late last year after nearly 10 months of captivity in a prisoner swap for Viktor Bout, a convicted Russian arms dealer known as the “Merchant of Death.”
In October, Iran briefly released Siamak Namazi, a 51-year-old dual-national Iranian American businessman who had been jailed since 2015, on a temporary furlough and lifted the travel ban on his father, Baquer Namazi, 85, a former official for the United Nations.
But Mr. Namazi is back in Iranian prison, and earlier this year went on a weeklong hunger strike to protest his detention. At the time, Karine Jean-Pierre, the White House press secretary, said that “Iran’s use of wrongful detention as political leverage is outrageous.”
Iran is also holding Emad Shargi and Morad Tahbaz. Mr. Tahbaz, 67, a businessman and conservationist, has been detained since 2018. Mr. Sharghi, also a businessman, was arrested in January. Both are being held by the Iranian government on charges of spying and threatening national security.
In January, Ms. Jean-Pierre said that the Biden administration was “continuing to work to bring him home, along with U.S. citizens who are wrongfully detained in Iran, including Emad Shargi and Morad Tahbaz.”