WASHINGTON (AP) — Rep. Jose Serrano, a 16-term Democrat from the South Bronx, said Monday he has Parkinson's disease and will retire at the end of his term.

The 75-year-old Serrano is a fixture in Bronx politics and is among Congress' foremost defenders of Puerto Rico, the U.S. territory where he was born.

He's chairman of a House Appropriations subcommittee with jurisdiction over the departments of Justice and Commerce, and he pledged to use that post to "fight for climate change research, a fairer justice system, and an accurate 2020 census count."

Serrano's announcement came shortly after New York City Councilman Ritchie Torres announced he'd run for the congressional seat, which is a lopsided Democratic stronghold that gave Hillary Clinton 94 percent of the vote against President Donald Trump. Serrano's announcement promises to lead more Democrats to enter the fray.

In his announcement, however, Serrano cited his diagnosis.

"Although this disease has not affected my work in Congress, over the last few months I've come to the realization that Parkinson's will eventually take a toll, and that I cannot predict its rate of advancement," Serrano said. Serrano said Parkinson's hasn't affected his work yet, but he has slowed in recent years.

Over almost three decades in Congress, Serrano has been a reliable vote for Democratic leaders and has focused much of his attention on the issues before the Appropriations Committee, such as funding legal aid for the poor, the Census, and revitalizing the economically troubled South Bronx.

"I am extremely proud of the work we did to revitalize the Bronx River, to bring billions of federal dollars to our borough, to expand access to the ballot for language minorities, to increase STEM resources for minority students," Serrano said. He also cited efforts to end the bombing of the island of Vieques, Puerto Rico, as part of U.S. training exercises.