New Jersey Sen. Frank Lautenberg will not seek re-election

New Jersey Sen. Frank Lautenberg announced on Thursday he will not seek re-election in 2014.

His decision comes after months of mixed signals from the longtime Democratic lawmaker as well as a potential primary challenge from Newark, N.J., Mayor Cory Booker, who formed a committee earlier this year to explore a Senate run.

Lautenberg said he would make a formal announcement on Friday in his hometown of Paterson, N.J.

“This is not the end of anything, but rather the beginning of a two-year mission to pass new gun-safety laws, protect children from toxic chemicals and create more opportunities for working families in New Jersey,” Lautenberg said in a statement. “While I may not be seeking re-election, there is plenty of work to do before the end of this term, and I'm going to keep fighting as hard as ever for the people of New Jersey in the U.S. Senate."

At 89, Lautenberg is the oldest member of the Senate, and rumors had been rampant for months that he would bow out of seeking a sixth term. But after Booker announced he would explore a potential run for Lautenberg's seat, the senator was clearly irked, implying to a reporter that the Newark mayor deserved a "spanking" for jumping into the race so early.

Lautenberg, a veteran of World War II, was a businessman and commissioner of the Port Authority of New York and New Jersey before he successfully won New Jersey's U.S. Senate seat in 1982. He served until 2001, when he retired. But he agreed to run again in 2002, when then-Sen. Robert Torricelli, who was seeking re-election, dropped out of the race amid an ethics scandal.

Lautenberg's retirement is likely to set off a heated Democratic primary in the race. In addition to Booker, Rep. Frank Pallone has also said he's interested in the race. On the Republican side, longtime television host Geraldo Rivera said earlier this month he's considering a run.

In a statement, Booker praised Lautenberg as a "champion of the people" and said "his legacy of service will improve the lives of all Americans for years to come."

"Sen. Lautenberg has been a strong model of leadership and service to me since before I even considered entering elected office," Booker added. "I look forward to continuing to work with him for the remainder of his term in senate and for many years to come."

President Barack Obama also issued a statement, calling Lautenberg a "steadfast champion of the people of New Jersey" whose service in the Senate and in World War II is "a testament to his character and deep commitment to public service."