Newark Mayor Cory Booker ended months of speculation Thursday when he announced that he was considering a run for US Senate.

“[ 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 said in a statement released shortly before noon.

Political observers in the state and beyond have speculated whether Booker, 43, a Rhodes scholar and Bergen County native, would run for governor against Chris Christie in 2013 or seek the Senate seat now held by Booker’s fellow Democrat Frank Lautenberg.

Lautenberg, at 88 the Senate’s oldest member, has not announced any plans to step down when his term expires in 2014. In his statement, Booker’s language suggested he was not looking to provoke a challenge to the veteran lawmaker. 

“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.” he said.

In July, Booker told an audience in Bergen County he was considering a run for US Senate or for governor. Polling in mid-October suggested Booker would pose a significant challenge to Christie, a Republican with whom Booker has a friendly relationship.

Following Christie’s performance during Hurricane Sandy, however, his popularity soared, leading many to speculate Booker would opt for the Senate seat instead. In recent days rumors swirled that Booker would indeed try for Senate instead of a tilt at Christie next year.

Booker was first elected mayor in 2006 on a promise of reform in a city where three previous mayors were each charged with corruption. As mayor, Booker has combined a progressive social agenda with a business-friendly approach to spurring development in the city. During his tenure, major corporations -- including Wakefern and Panasonic - have decided to open corporate offices and facilities in the struggling community, where tens of thousands are in poverty.

The mayor also projects a distinct aura of celebrity. He has 1.3 million followers on Twitter. His hands-on approach to governance -- including responding personally, and in person, to complaints about problems like a lack of snow removal, have made him a national figure. In 2010, Facebook founder Mark Zuckerberg donated $100 million to Newark schools after meeting with Booker.

His popularity nationally grew even larger after he rescued a woman from her burning apartment earlier this year.

Closer to home, however, Booker has his critics, who have complained he spends too much time outside the city on media appearances and lucrative speaking engagemements. He also drew fire this year after attempting to create an independent authority to oversee the city’s water system, a move long resisted by many Newarkers.

Last month, Booker’s vote for a replacement to a vacant municipal council seat sparked a riot at city hall by people who said the mayor was attempting to usurp the democratic process.