(CNN) - Newark Mayor Cory Booker will not challenge New Jersey Gov. Chris Christie in next year's gubernatorial race and will instead explore a run for U.S. Senate, Booker announced Thursday.
Booker will run to replace fellow Democrat Sen. Frank Lautenberg when his term is up in 2014. Lautenberg, who will turn 89 in January, is the oldest currently serving senator and has not indicated if he will run for reelection.
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"Let there be no doubt, I will complete my full second term as mayor. As for my political future, I will explore the possibility of running for The United States Senate in 2014," Booker wrote in an op-ed in New Jersey's Star-Ledger.
"As I explore a run for the United States Senate, I look forward to consulting with Senator Lautenberg. During my lifetime, he has been one of New Jersey's most important leaders. It would be a privilege to continue his great legacy of service."
"I believe it is in the interests of Newark that I get fully involved in New Jersey's 2013 elections," he continued. "No one will fight harder than me for the Democratic ticket this fall, from the top to the bottom. Newark is my city, New Jersey is my State – I intend to be of service to them both now and for the rest of my life."
Christie's approval ratings spiked following his response to Superstorm Sandy, and polls pitting the two Garden State leaders against each other show the Republican governor ahead in a potential gubernatorial match up. A poll from Quinnipiac University, taken November 19-25, showed Christie with a 53%-35% lead over Booker.
Christie, speculated to have 2016 White House aspirations, announced in late November that he would seek reelection as New Jersey's governor. New Jersey and Virginia are the only two states to hold gubernatorial contests next year.
Booker's announcement opens the field for other Democrats running for New Jersey governor, including New Jersey state Sen. Barbara Buono who officially announced her bid for governor in an email to supporters earlier this month.
Other Democrats considering running for the governor's office are state Sen. Richard Codey – who served as governor for 14 months following the November 2004 resignation of then-Gov. Jim McGreevey – as well as Assembly members Lou Greenwald and John Wisniewski.
In a statement Wednesday, Lautenberg spokesmen Caley Gray said the senator is not focused on politics right now.
"Senator Lautenberg is focused on passing a critical disaster relief bill for New Jersey and addressing America's broken gun laws," Gray said. "The last several months and weeks have been a painful time for New Jersey and America, and the Senator is working on the tough issues we face. This is not the time for political distractions and the Senator will address politics next year."
Booker, who gave a prime time address at the party's convention, is considered a rising star in Democratic Party. He announced earlier in December that he would make a decision on whether to challenge Christie within the month.
CNN's Paul Steinhauser, Kevin Liptak and Dana Davidsen contributed to this report.