Florida Sen. Marco Rubio defended Mitt Romney's position on immigration this morning, as the presumed Republican presidential nominee prepares to address Hispanic elected officials this afternoon.

Romney "doesn't have an immigration bill per se, but neither does the president," Rubio said. "This is not an issue that's easily solved on the campaign trail."

The Republican senator said Romney "understands that immigration is important for our country, and he understands the legal mechanisms are broken and need to be fixed."

Romney will address the National Association of Latino Elected Officials in Orlando today.

Rubio told reporters he was critical of President Obama's decision last week to suspend deportations of foreign-born young people brought to the United States as children by their parents. Obama's executive order, he said, makes it more difficult to reach a permanent solution.

The Cuban-American senator has been crafting his own version of the DREAM Act, but said there are some thorny issues about how to balance compassion with enforcement that Obama's order doesn't address. "If I wanted a talking point, I would have filed a bill six months ago," he said.

On tour to promote his new political memoirs, An American Son, Rubio was playful with the ballroom of reporters attending a breakfast sponsored by the Christian Science Monitor. "Thank you for the invitation. I was not aware that there would be press here today," he joked.

Asked whether Romney was vetting him for vice president, he said, "I don't talk about the process at all -- but I have a new book!"

USA Today