A veteran US senator has temporarily stepped down as head of the chamber's powerful foreign relations committee as he battles bribery charges.
Justice department prosecutors allege Robert Menendez and his wife accepted hundreds of thousands of dollars in exchange for aid to Egypt's government.
The couple have denied the charges.
The embattled senator has rejected calls from fellow Democrats back in his home state of New Jersey to resign his seat.
Senate majority leader Chuck Schumer said on Friday that Mr Menendez had decided to step down as chairman of the influential committee "until the matter has been resolved".
The New York Democrat said his colleague was "a dedicated public servant and is always fighting hard for the people of New Jersey".
It is not the first time that Mr Menendez, 69, who has served in Congress since 2006, has had to give up the coveted post on the foreign relations panel.
He also stepped down in 2015 after being indicted in New Jersey on charges that he had accepted bribes from a Florida eye doctor. That case ended in a mistrial after jurors were unable to reach a unanimous verdict.
Maryland Democrat Ben Cardin, who took over as the committee's leading Democrat at the time, is expected again to temporarily ascend to fill the vacancy.
Mr Menendez and his spouse, Nadine Arslanian, are accused of accepting bribes of cash, gold, payments towards a home mortgage and a luxury vehicle from three New Jersey businessmen.
Prosecutors allege the pair accepted the money to secretly aid the Egyptian government and to enrich the three men: Wael Hana, Jose Uribe and Fred Daibes.
According to the 39-page indictment unsealed on Friday, Mr Menendez's leadership position and power as a senator enabled such influence-peddling.
The pair each face three criminal counts: conspiracy to commit bribery, conspiracy to commit honest services fraud, and conspiracy to commit extortion under colour of official right.
In a statement from her lawyers, Mrs Menendez denied any wrongdoing and said she would defend herself in court.
Mr Menendez sought to portray the allegations as politically motivated.
"For years, forces behind the scenes have repeatedly attempted to silence my voice and dig my political grave," he said in a lengthy statement.
"Since this investigation was leaked nearly a year ago, there has been an active smear campaign of anonymous sources and innuendos to create an air of impropriety where none exists."
"I am confident that this matter will be successfully resolved once all of the facts are presented and my fellow New Jerseyans will see this for what it is," he added.
But a wave of top Democrats, including at least four members of Congress from New Jersey, called for the lawmaker to resign.
In a statement, New Jersey Governor Phil Murphy said the allegations were "so serious that they compromise the ability of Senator Menendez to effectively represent the people of our state".
"Therefore, I am calling for his immediate resignation," he wrote.
Under New Jersey law, if Mr Menendez resigns from the Senate, the governor would appoint a temporary replacement to serve out the rest of his term.
But any delay between resignation and temporary appointment could pose headaches for Democrats in a Senate they control by a one-seat margin.
The White House, for whom Mr Menendez is a key foreign policy ally, has so far declined to comment.
In a defiant second statement on Friday, Mr Menendez vowed: "I am not going anywhere."
His indictment comes after a years-long justice department investigation.
In the summer of 2022, federal agents executed search warrants at Mr Menendez's home and found evidence of the bribery agreements, including over $480,000 (£390,000) in cash, much of which was "stuffed into envelopes and hidden in clothing, closets and a safe", prosecutors allege.
Agents said they also found a Mercedes-Benz luxury vehicle paid for by Mr Uribe parked in the garage, as well as $100,000 of gold bars in the home, pictures of which were included in the indictment.
As a result of the charges, Mr Menendez and his wife have been asked to forfeit several assets, including their New Jersey home.
In a statement to US media, a spokesperson for Mr Hana said: "We are still reviewing the charges but based upon our initial review, they have absolutely no merit."
The BBC has reached out to businesses owned by Mr Daibes for comment. The Embassy of Egypt in Washington DC did not respond to a request for comment.
Mr Menendez, his wife and their three co-defendants are scheduled to appear in Manhattan federal court on 27 September.