Russia has freed Stephen Hubbard, a 74-year-old retired teacher from Michigan who had been imprisoned for more than four years on charges that he fought as a mercenary for Ukraine. Vladimir Putin said during a meeting in St. Petersburg on Wednesday with Steve Witkoff, President Trump's special envoy, that Hubbard was at the city's Pulkovo airport, and Witkoff thanked the Russian leader for the release.

The release came a day after Trump said he had asked Putin to let Hubbard go. "I've been talking to him at length. I've asked him to release him. Let's see what happens," Trump told reporters in the Oval Office on Tuesday, The Moscow Times reported. Before the trip, a U.S. official said Witkoff's visit was expected to include efforts to win Hubbard's freedom, "reflecting President Trump's continued commitment to bringing Americans home."

The State Department had designated Hubbard as wrongfully detained. Russia's state-run TASS news agency quoted Putin as saying Hubbard was preparing to board a flight back to the United States, according to The Moscow Times. Reports by CNN and NBC News did not say when he would arrive, and neither described a prisoner exchange or any other condition attached to the release.

Hubbard spent decades abroad teaching English. In 2014 he settled in Izyum, a city in eastern Ukraine that Russian forces occupied at the start of the war in 2022, and he was taken from his home in Ukraine after the full-scale invasion. Russian prosecutors alleged that he fought in Izyum after signing a contract that paid about $1,000 a month, according to Russian state media accounts cited by CNN. His sister, Patricia Hubbard Fox, has called that accusation a lie, and Hubbard denies the charges.

Witkoff landed at Pulkovo on Wednesday morning and was met by Kirill Dmitriev, Putin's envoy for investment. Yuri Ushakov, a Kremlin adviser, said Ukraine would dominate the conversation at the Constantine Palace, NBC News reported.

The St. Petersburg meeting followed a session in Oslo on Tuesday at which Witkoff and other U.S. negotiators met Ukrainian President Volodymyr Zelenskyy along with the leaders of Norway and Finland. A U.S. official said Ukraine brought new ideas and proposals to that meeting and that "meaningful progress" was made, adding that the aim in St. Petersburg was to build on it and open a path toward direct negotiations. Secretary of State Marco Rubio called the Oslo talks "positive" but said "nothing unexpected" came out of them.

The wider peace effort has drawn criticism at home and abroad over what NBC News described as a series of apparent moves to withhold support from Ukraine and align more closely with Russia. The Kremlin has shown little sign of retreating from demands that include control of Ukraine's entire eastern Donbas region.

Hubbard's release follows that of Robert Gilman, a Marine veteran whom Russia let go in August on humanitarian grounds amid severe concerns about his health, CNN reported. Other Americans are still held in Russian prisons, among them Andre Khachatoorian, who was detained in 2021 and sentenced to eight and a half years on arms trafficking charges he denies, and David Barnes, who was arrested in 2022.