Sen. Judd Gregg, who is retiring from Congress this year, said Monday that it was “inappropriate” of him to briefly accept President Barack Obama’s offer to serve as Commerce secretary in 2009.

“I made a mistake in saying yes,” the New Hampshire Republican said during an interview on Fox Business Network.

Gregg, the Budget Committee ranking member, was offered and accepted the Commerce post in February 2009. But less than two weeks later, he backed out because, he now says, he realized he had gotten caught up “in the euphoria of the moment.”

“It was really inappropriate because … I really thought maybe I could go in and contribute in a constructive way. I would have wanted to. But when you’re in the Cabinet, you’ve got to be with the president 100 percent of the time,” Gregg said.

White House spokesman Robert Gibbs said in a statement at the time that the administration parted ways with the Republican Senator “once it became clear … Gregg was not going to be supporting some of President Obama’s key economic priorities.”

The New Hampshire Republican demurred Monday when asked about Obama’s reaction to the situation.

“I’ve never talked about that,” he said. “But he was extraordinarily gracious about it. And I’ve always admired him for that.”