LOS ANGELES (AP) Despite severely trimming his lagging campaign to cut costs, Newt Gingrich vowed Wednesday to stay in the Republican presidential race until front-runner Mitt Romney has the necessary support to become the nominee.

Until Romney has won the 1,144 convention delegates it takes to win the nomination, Gingrich said "I owe it to the people that helped me for the last year to represent their views and their values."

He bristled at the pressure building on him and Rick Santorum to drop out and make way for Romney.

"For some reason everybody in the establishment is chanting that Santorum and I should quit," Gingrich told Washington, D.C., radio station WTOP. "Romney has to earn this. It's not going to be given to him."

But Gingrich still intends to support Romney if he gets the required number of delegates before the party's national convention in Tampa, Fla., in August, said Gingrich spokesman R.C. Hammond.

One-third of Gingrich's campaign staff has been laid off and campaign manager Michael Krull was asked to resign, Hammond said Tuesday night. Hammond and communications director Joe DeSantis will stay on.

The new strategy calls for the former House speaker to spend less time in primary states and more time trying to persuade delegates to back him at the Republican National Convention. The campaign's focus also is expected to begin emphasizing digital outreach, in particular YouTube, Twitter and other social media.

This latest reshaping of Gingrich's campaign came after he reported more than $1.5 million in outstanding debt by the end of February, according to Federal Election Commission filings, including legal fees and advertising production costs. At the same time, he had about $1.5 million cash on hand, the least of the four GOP candidates.

"Cash flow was shorter than we'd like it to be, so we're doing the appropriate things to be able to campaign," he said Wednesday.

Santorum, who is challenging Gingrich for the anti-Romney vote among conservatives, responded to the news by urging Republicans to back his effort, not Romney's.

"I think it is time for all the Republican candidates to coalesce behind me," Santorum said Tuesday in Delavan Lake, Wis. "You know, let's just have a conservative nominee to take on Barack Obama. Until that time happens, I'm not going to call on anyone to get out."

Hobbled by weak fundraising and well behind Romney in the hunt for delegates, Gingrich has been under growing pressure to help unify Republicans by dropping out of the race.

In a nod to those who think he should give way to Romney, Gingrich pledged Tuesday to support Romney if the former Massachusetts governor wins the needed number of delegates by the end of the GOP primary season in June.

"Obviously I will support him and will be delighted to do anything I can to help defeat Barack Obama," Gingrich told reporters as he campaigned in Annapolis, Md. Republicans vote in Maryland's primary next week.

If Romney falls short, Gingrich said, "I think you'll then have one of the most interesting, open conventions in American history."

Gingrich tried to position himself as an anti-establishment figure in the race while playing up the 20 years he spent in the House, including several years as speaker. He has struggled since his campaign peaked just before the Iowa caucuses in January. Devastating attacks from Romney and a Romney-aligned super PAC have helped deny him further victories. He has won just two primaries, in South Carolina and Georgia, and has less than 15 percent of the delegates so far.

Gingrich had hoped for a Southern-based comeback, but Santorum won contests in Mississippi, Alabama and Louisiana.

Romney is the leader with 568 delegates, based on a tally by The Associated Press. That is slightly less than half the needed 1,144, and more than four times as many delegates as Gingrich, who has 135.