A joint invitation to participate in a town-hall style meeting in July was extended to Sens. Barack Obama and John McCain from Simi Valley's Reagan Library and the Johnson Library in Texas, officials announced Thursday.

Obama and McCain, the presumptive presidential nominees, have indicated a willingness to participate in such a forum, but neither campaign immediately commented on the invitation.

Nancy Reagan, and Lynda Johnson Robb and Luci Baines Johnson extended the invitations to the candidates.

"The Reagan Library is honored to participate in this historic, bipartisan dialogue," Reagan said in a statement.

Recently, McCain asked Obama to join him in 10 town hall meetings with voters in the coming months, and their campaigns began negotiations to make it happen. McCain, the Republican nominee-in-waiting, made the request the day after Obama clinched the Democratic nomination.

"This is obviously a response to that," said Melissa Giller, spokeswoman for the Reagan Library.

Giller said the idea came about when the two chairs of the presidential library foundations came together a week ago to discuss the possibility of both facilities hosting town hall meetings, unprecedented in the history of modern presidential campaigns.

While details of the meeting await a response from the two presidential hopefuls, an independent polling organization will be brought in to make sure audiences will represent a cross-section of the American people, Giller said. Candidates will be given equal access to address key issues through audience questions.

The town hall meetings will come before the two national conventions later this summer and the start of the traditional series of presidential debates in September and October.

Both the Reagan and Johnson libraries have held presidential debates in the past year, so both campuses' staffs have the experience to put on such an event, Giller said.

On Feb. 21, the Lyndon Baines Johnson Library and Museum, on the University of Texas at Austin campus, held a debate between the two remaining Democratic candidates, Obama and Sen. Hillary Rodham Clinton.

At the Ronald Reagan Presidential Library and Museum on Jan. 30, the Air Force One Pavilion was the site of the second presidential debate, with the four remaining Republican candidates.

"In the bipartisan spirit of the presidential library system, my father would be proud of this opportunity for Americans to embrace a Scripture verse he quoted often, Come, now, let us reason together,'" said Robb in a statement.

Bill Gallaher, chairman of the county Democratic Central Committee, said a bipartisan event like this would be good for the Reagan Library and Ventura County.

"If this materializes, I'd love to go," Gallaher said.

— The Associated Press contributed to this report.