President Bush plans to help John McCain fill his coffers at a high-dollar fund-raiser at the end of May, marking the first time the commander in chief has joined the Arizona senator for a campaign event since he wrapped up the nomination.

The reception is set for May 27 at the Phoenix Convention Center and is for donors who give $25,000 or more.

According to an article in The Politico, the money will be split between McCain campaign accounts and the Republican National Committee.

Bush, who endorsed McCain on March 5 after he wiped out most of the remaining competition in the GOP primary, is expected to hit the money trail with former GOP candidate Mitt Romney the next day.

They plan to hold fund-raisers with major donors in Salt Lake City and Park City, Utah.

FOX News' Mosheh Oinounou contributed to this report.