Updated 5:03 p.m. ET

Former president George H.W. Bush says Mitt Romney is the "best choice" for the GOP presidential nomination, but stopped short of giving a formal endorsement to the ex-Massachusetts governor.

In comments published today by the Houston Chronicle, the 41st president made clear he believes Romney is the "most electable" in the GOP field. He was careful not to offend his home-state governor, Rick Perry, whom Bush said he likes.

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Bush also explained he's not a fan of Newt Gingrich, who worked against the president when he had to renege on his "no new taxes" pledge to get a 1990 budget deal with Democrats.

"I think Romney is the best choice for us," Bush told the Chronicle in an interview this week. "I like Perry, but he doesn't seem to be going anywhere; he's not surging forward."

Bush is quoted as saying Romney has "stability, experience, principles" and is "mature and reasonable -- not a bomb thrower."

As for Gingrich, Bush said, "I'm not his biggest advocate."

Romney, campaigning in New Hampshire today, said he had "no idea" Bush would be coming out with supportive words.

Bush called Romney and spoke to the candidate in between stops on his New Hampshire bus tour. "I thanked him for his support, his leadership, his heroic life, and his friendship," Romney is quoted as saying by ABC News about his conversation with Bush." This is much more important to me personally than even politically."

Romney visited Bush and his wife, Barbara, at their home earlier this month while he was raising money in Houston. Bush was friends with Romney's father, George, a former Michigan governor and Nixon-era Cabinet official.