Newark, N.J. Mayor Cory Booker has filed papers to create a campaign committee to the Federal Election Commission, further signaling that the mayor is running for U.S. Senate in 2014.

The committee, "Cory Booker for Senate," submitted its papers on Tuesday.

Booker has not officially announced that he is running for Senate. However, in a Newark Star-Ledger op-ed on Dec. 20, he said that he was exploring the possibility.

Booker is aiming to run for the seat held by Sen. Frank Lautenberg (D-N.J.), who will be 90 in 2014. But Lautenberg hasn't announced that he's retiring or running yet.

The Newark mayor said Monday on CNN that Lautenberg has a "decision to make" about whether to run again, but he wants to "give him the space" to do so. A recent poll by Fairleigh Dickinson University PublicMind showed Booker leading Lautenberg by a 42-20 margin in a head-to-head matchup.

When reached by The Huffington Post, the mayor's office indicated it would provide comment shortly.

UPDATE: 4:45 p.m. -- Booker's political director Mark Matzen told The Huffington Post in a statement later Friday that the filing is part of the consideration for a Senate run.

"Today, Mayor Booker filed papers to be prepared for a possible US Senate campaign, but his focus remains on completing his vision for a revitalized Newark -- more than a billion dollars in economic development this year alone, reforming education for our kids, building housing and parks, and continuing to make progress in reducing crime and violence in the city," Matzen said. "As part of the process of exploring a possible senate run, the law requires any expenses in such an exploration to come from a federal account."

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