Maryland Gov. Martin O'Malley. (AP Photo/Jae C. Hong, File)

Maryland Gov. Martin O’Malley plans to return to New Hampshire late next month, making his fourth trip to the early presidential nominating state since November.

O’Malley (D) has been booked as the keynote speaker at the Portsmouth City Democrats fall dinner on Sept. 26, aides confirmed Friday.

The trip is part of a busy travel schedule for O’Malley, who has said he is preparing for a potential 2016 White House bid regardless of whether Hillary Rodham Clinton decides to run.

O’Malley was last in New Hampshire earlier this month, where he appeared at picnic to benefit the Strafford County Democrats and a fundraiser for the New Hampshire Senate Caucus.

O’Malley is also preparing to send more than dozen campaign staffers to New Hampshire and other states with competitive gubernatorial and U.S. Senate races this fall. In past cycles, potential presidential candidates have employed a similar strategy to build good will among politicians who could help them down the road.