His conviction was later thrown out because of prosecutorial misconduct, and he died in a 2010 plane crash.
The Menendez case was the first major federal bribery trial since the US Supreme Court in 2016 threw out the conviction of Republican former Gov.
The most serious charge against Menendez, honest services fraud, is punishable by up to 20 years in prison.
To those who embraced me in my darkest moments, I love you,' Menendez said.
'To those who were digging my political grave so they could jump into my seat, I know who you are and I won't forget you.'Menedez said he plans to return to the Senate as soon as possible.'I have served with honesty and integrity, and have given it my all every day,' Menendez said.
He also thanked those that helped him raise millions for his legal defense fund.
US District Judge William Walls declared the mistrial after more than six full days of deliberations that had to be re-started midway through when a juror was replaced.
Menendez's lawyers contended also that the government failed to establish a direct connection between Melgen's gifts and specific actions taken by the senator. Melgen, they said, essentially put Menendez on the payroll and made the politician his 'personal senator,' available as needed.