The Justice Department filed a one-paragraph notice of intent to retry the case and asked U.S. District Court Judge William H. Walls for the earliest possible trial date.
Menendez and his longtime friend, a Florida eye doctor named Salomon Melgen, were indicted in 2015 on bribery and corruption charges.
Prosecutors said Menendez pressured government officials on Melgen's behalf over an $8.9 million Medicare billing dispute and a stalled contract to provide port screening equipment in the Dominican Republic, and also helped obtain USA visas for the doctor's girlfriends.
During the month of December, Menendez said it was unlikely that prosecutors would continue with the case, but if they did, he added: "Bring it on".
In exchange, prosecutors charged, the New Jersey Democrat helped Melgen's foreign mistresses secure visas, intervened in a multimillion-dollar Medicare dispute and pressured US officials to safeguard a lucrative port security contract in the Dominican Republic. "Senator Menendez fully intends to be vindicated-again".
The hung jury in the first trial voted 10 to 2 to acquit Menendez, suggesting they did not believe the prosecution's case as it was presented. Menendez faces re-election this year.
Randall Eliason, a law professor at George Washington University, said a request for a retrial was always likely because prosecutors would not have brought the case in the first place unless they felt it was strong.
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The Justice Department said it plans to re-try Sen.
After the mistrial, Menendez quickly reengaged in his Senate duties - especially on immigration, an issue of special importance given that he is the longest-serving Latino in the chamber.
In a separate case in Florida, Melgen awaits sentencing after being convicted past year on 67 counts of Medicare fraud that prosecutors say exceeded $100 million.
Mr. Menendez had been charged with 12 counts of corruption, including six counts of bribery and three counts of honest services fraud.
Menendez's lawyers also contended also that the government failed to establish a direct connection between Melgen's gifts and specific actions taken by the senator.
"Defense attorneys in their opening statements and closing arguments during the first trial "made baseless accusations of racial animus on the part of the Government", that invited the jury to consider the defendants' ethnicity and political affiliation in resolving the charges against them", prosecutors wrote.
Similarly, when several State Department witnesses testified that Menendez had threatened to hold a congressional hearing if they did not intervene in a contract dispute between Melgen and the Dominican Republic over cargo screening at the nation's ports, the defense said the senator was troubled by port security more generally.