Mr Menendez has been the US Senator for New Jersey since 2006.
He was the top-ranking Democrat on the powerful Senate Foreign Relations Committee for more than five years, a position that gave him significant influence over US foreign policy.
The son of Cuban immigrants, he is among Capitol Hill’s most prominent Latino lawmakers and has been an outspoken advocate on immigration policy.
Mr Menendez has faced federal corruption charges before. He was tried in 2017, with the justice department alleging he did political favours for a wealthy Florida eye doctor in exchange for luxury holidays and other lavish gifts.
But that case ended in a mistrial after he was acquitted on some charges and jurors were unable to reach a unanimous verdict.
Facing a second indictment, Mr Menendez has stepped down from his chairmanship of the foreign affairs panel and has said he will not run for re-election as a Democrat.
But he has resisted bipartisan pressure to resign from the Senate, adding that he may seek to hold on to his seat with an “independent Democrat” candidacy if he is acquitted this summer.
