Governor Chris Christie delivered a calm attack on President Obama to wrap up Mitt Romney's appearance at the Republican Governor's Association meeting in Aspen, Colorado.

Romney introduced Christie as the closer in what could be seen as a possible preview of a keynote address at the upcoming Republican National Convention.

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Christie compared his dealing with New Jersey's deficit to how Romney in the White House should deal with the federal deficit. "The American people are not afraid to hear the truth," he said according to the Star Ledger.  "The American people are tired of having a happy song sung to them."

Christie said the problem with Obama's presidency is that "He’s missed the core issue that’s made his presidency fail," Christie said. "The core reason that his presidency has failed is he doesn’t know how to lead.

Romney says he's looking forward to working with GOP governors like Christie, Nikki Haley of South Carolina and Virginia's Bob McDonnell.Those governors and others joined Romney at a rally Thursday in Aspen, where the Republican Governors Association is meeting.

Other attendees include Govs. Bobby Jindal of Louisiana and Susana Martinez of New Mexico.

Romney is expected to announce his running mate any day.

Haley says she'll fight to get Romney elected. McDonnell says Romney is focused on the middle class.

The Associated Press contributed to this story.