Barack Obama Congratulates Mitt Romney In Personal Phone Call

The race is officially on.

President Barack Obama called Mitt Romney on Wednesday to congratulate him on clinching the Republican nomination, after the former Massachusetts governor received more than 100 delegates in the Texas primary the previous evening.

"President Obama said that he looked forward to an important and healthy debate about America's future, and wished Governor Romney and his family well throughout the upcoming campaign," Obama for America spokesman Ben LaBolt said in a statement.

A Romney campaign aide, who asked not to be identified, said in an email that the call "was brief and cordial."

"Gov. Romney thanked the President for his congratulations and wished him and his family well," the Romney aide said.

The call took place at about 11:30 a.m. Eastern time, LaBolt said.

The two men previously shared cordial words; they shook hands and wished each other good luck in 2007 while campaigning in New Hampshire.

Although Obama and Romney have doggedly attacked each other -- and allowed their campaigns to do the same -- during the campaign, they have both said they personally respect their opponent. Obama called Romney "a patriotic American who has raised a wonderful family, and he has much to be proud of" in May, while Romney has called the president "a nice guy."

Jon Ward contributed reporting.