Sen. John McCainJohn Sidney McCainSenate Dems tell Trump: Don't meet with Putin one-on-one McConnell: Senate to confirm Kavanaugh by Oct. 1 Overnight Defense: Fears rise over Trump-Putin summit | McCain presses Trump to hold Putin 'accountable' for hacking | Pentagon does damage control after NATO meet MORE (R-Ariz.) argued Tuesday that his relationship with President Obama is fine, contrary to media reports that the two had become distant in recent weeks.

"I'm the loyal opposition," McCain said during an interview with Fox News's Neil Cavuto Tuesday afternoon. "The country's in too bad of shape for us to not work together."

Still, McCain vowed to stand on principle -- even against members of his own party -- when necessary, especially on earmarks, which the former Republican presidential nominee said plagued both parties.

Signals were that the relationship between the two sparring partners this past fall had waned.

"It's a bipartisan disease, and we don't seem to get it," McCain said of the earmarks in the omnibus bill inserted by lawmakers on both sides of the aisle. "It is a habit, and it's become corruption."

McCain said it would be "disgraceful" for the president to sign such a package into law.