Jae C. Hong, Associated Press
Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks at the RNC State Chairman's National Meeting in Scottsdale, Ariz., Friday, April 20, 2012.

PHOENIX — Mitt Romney is assuming his new role as leader of the Republican Party as his campaign works to integrate with the Republican National Committee.

On Friday, the presumptive GOP presidential nominee addressed a gathering of state GOP chairs and members in Phoenix. Reading from a list, he rattled off the names of his primary challengers and thanked them, saying they "fought hard and well." The listed included Newt Gingrich and Ron Paul, who are still campaigning against him.

Sen. John McCain, the party's 2008 nominee, and RNC Chairman Reince Priebus (ryns PREE'-bus) introduced Romney to the gathering of about 200 people.

Priebus told the former Massachusetts governor he wanted to welcome him "in a formal way, to greet a family here."