The city's Puerto Rican community is demanding the release of a political prisoner from the island.
City Council Speaker Melissa Mark-Viverito joined Puerto Rican advocacy groups outside of City Hall to raise awareness about Oscar Lopez Rivera.
They're asking New Yorkers to join them at a rally outside of the White House Sunday to push for Rivera's release.
The 73-year-old was arrested on conspiracy charges while fighting for Puerto Rican independence in 1981.
He's been in prison ever since and has spent 12 years of his sentence in solitary confinement.
Advocates are calling on President Barack Obama to pardon Rivera before he leaves office in January.
"The support for Oscar is international, and in Puerto Rico, on the island, it is universal across party lines. In a united voice, the Puerto Rican community is saying that 35 years is enough, and Oscar Lopez Rivera has to be returned to his family and to his island. And so that is what we are asking for, and that is the purpose of the mobilization on Sunday," the speaker said.
Advocates say hundreds are expected to travel to Washington for the rally.