KITTERY — The New Hampshire man who pleaded guilty to setting fire to a nuclear-powered submarine but now says he doesn’t think he committed the crime has requested more time to respond to a magistrate’s recommendation that his appeal be dismissed.

A federal magistrate a month ago rejected Casey James Fury’s claim of ineffective counsel leading up to his guilty plea and sentencing for the fire in May 2012.

Fury, who’s serving a 17-year sentence, told the Portsmouth Herald in a story published Sunday that he believes his confession was coerced and said he doesn’t remember setting the fire that damaged the USS Miami at Portsmouth Naval Shipyard in Kittery, Maine.

He said he wants a judge to reconsider his sentence based on claims including substance abuse, mental health problems and evidence that he contends weren’t adequately addressed by his lawyer.

David Beneman, his court-appointed attorney, declined comment.

Fury, who is representing himself, was given until June 5 to appeal the federal magistrate’s recommendation that his claim be rejected.

Prosecutors disagreed with Fury’s claim that he received ineffective counsel. They also contend there’s no doubt about who set the fire.

Prosecutors said the shipyard worker was suffering from anxiety and set the fire because he wanted to go home. In addition to confessing, Fury described in detail his actions to investigators during walk-throughs aboard the USS Miami and a similar submarine.

Prosecutors had no immediate comment but planned to issue a statement later on Monday.

The fire started in a forward compartment and turned into an inferno that required 12 hours and more than 100 firefighters to douse. Seven people were hurt and damage was so extensive that the Navy ultimately decided to scrap the submarine.

Fury, 27, is serving his sentence at a federal prison in New Jersey after pleading guilty to setting two fires aboard the submarine.

He told the newspaper he didn’t remember reporting to work on the day of the big fire but acknowledged setting a smaller fire that caused superficial damage outside the submarine about two weeks later. He also acknowledged pulling a fire alarm three days later.