Republican presidential candidate Mitt Romney criticized the Obama administration’s domestic and foreign policy during an interview on Fox News Sunday, expressing confidence that he will be the GOP hopeful to challenge the president in November.

Romney pointed to the recent tension between the U.S. and Afghanistan as an example of Obama’s “failed leadership.”

"Look, what's happening right now,” the former Massachusetts governor said. “The president put out a specific time table...that is leading [Afghan President Hamid Karzai] to take action that is self preservation in nature.”

Romney also accused President Obama of waiting too long to impose sanctions on Iran and not making it clear that the U.S. was prepared to take military action if necessary in preventing Iran from developing nuclear weapons, according to Fox News.

On Obama’s handling of domestic issues, Romney ripped the president for rising gas prices. Romney also told Obama to fire advisers who he blamed for those price increases.

"The secretary of energy, the secretary of interior and EPA administrator...this gas hike trio has been doing the job over the last three and a half years, and gas prices are up,” Romney said.

The GOP frontrunner leads main rivals Rick Santorum and Newt Gingrich in the delegate count, but his inability to generate support among conservative voters has seemingly stalled his climb toward the 1,144 delegates needed to secure the party’s nomination.

The U.S. commonwealth of Puerto Rico holds its primary today with 23 delegates at stake, while Illinois will have 69 delegates for the taking in Tuesday’s lone primary contest. Arizona Sen. John McCain, who beat out Romney for the GOP nod in 2008, said his one-time rival is “improving dramatically” as a candidate, during an interview on NBC’s Meet The Press.

“Obviously Mitt Romney will tell you first of all he's got to do a better job. He's working on doing a better job,” McCain said in an article in The Hill. “He's got to focus more on the economy."

McCain dismissed suggestions that Romney’s inability to pull away from Santorum, Gingrich and Rep. Ron Paul could result in a brokered convention when GOP delegates meet in Tampa in August.

“I just don’t think it’s going to happen,” McCain said. “This is the nastiest fight I’ve ever seen. It’s gone on too long, and it’s gotten way, way too personal.”

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