Adams faces five criminal charges in total, including conspiracy to commit wire fraud.
Prosecutors said he sought and accepted benefits including luxury travel from wealthy foreign businesspeople and a Turkish government official seeking to gain influence over him.
Earlier on Thursday, federal agents searched the mayor's Gracie Mansion home on Manhattan's Upper East Side.
A black sport utility vehicle with a placard reading "Federal Law Enforcement" on its dashboard was parked outside the residence, according to a Reuters witness.
Authorities carrying folders were seen leaving the residence of New York City mayor Eric Adams. (AP PHOTO)
About a dozen people in business attire were seen walking on to the mansion's grounds with briefcases and duffel bags, the witness said.
Adams' lawyer Alex Spiro accused authorities of trying "to create a spectacle" and said they had taken the mayor's phone.
Spiro said Adams "looks forward to his day in court".
Adams, a Democrat who became the first of the city's 110 mayors to be criminally charged while in office, said in a video statement on Wednesday night that he expected to be charged - and that the accusations would be "entirely false, based on lies".
In his video message, Adams vowed to remain in office while fighting any charges, defying calls from other Democratic politicians to resign.
"If I'm charged, I know I'm innocent. I will request an immediate trial so New Yorkers can hear the truth," Adams said.
New York state governor Kathy Hochul, also a Democrat, has the power to remove Adams from office but the process is complicated, said Bennett Gershman, a professor at Pace University Law School in Manhattan.
The case is likely to complicate any Adams bid for re-election in 2025.
Other Democratic politicians, including New York City comptroller Brad Lander, plan to challenge Adams - once a key ally of US President Joe Biden - for the party's nomination.
Before the news broke that Adams had been indicted, US Representative Alexandria Ocasio-Cortez, also a Democrat, became the first member of Congress to urge him to step down, saying it would be "for the good of the city".
The New York Times, citing a search warrant, reported in early November 2023 that federal authorities were investigating the possible acceptance by Adams' 2021 campaign of illegal donations, including by the Turkish government.
The probe, conducted by the US Attorney's office in Manhattan, focused on whether Adams' 2021 mayoral campaign conspired with a Brooklyn construction company to funnel foreign money into the campaign through a straw-donor scheme, the NYT said.
Authorities have also sought information about Adams' interactions with Israel, China, Qatar, South Korea and Uzbekistan, according to the NYT.
Adams, 64, a former police officer who rose to the rank of captain, has repeatedly denied wrongdoing and said he is co-operating with the probe.
New York has been in a state of political upheaval for the past month.
Police Commissioner Edward Caban resigned on September 12, a week after FBI agents seized his phone.
Days later, Adams' chief legal adviser resigned, saying she could "no longer effectively serve" in the position.
On Wednesday, the city's public schools chancellor David Banks said he would retire at the end of the year, weeks after the NYT reported his phones were seized by federal agents.
