US Republican presidential candidate Mitt Romney raised questions about US President Barack Obama’s approach to foreign leaders Wednesday after he won three primaries and moved closer to clinching the GOP nomination

US Republican presidential candidate Mitt Romney raised questions about US President Barack Obama’s approach to foreign leaders Wednesday after he won three primaries and moved closer to clinching the GOP nomination, Haaretz reported.

Speaking to the Newspaper Association of America the day after he prevailed in the Wisconsin, Maryland and District of Columbia votes, Romney attacked Obama for having been caught on a live microphone last week telling Russian President Dmitry Medvedev that he would have “more flexibility” to deal with controversial issues like missile defense after the November election.

Calling the comment “deeply troubling,” Romney charged that “that incident calls his candor into serious question.”

“What exactly does President Obama intend to do differently once he is no longer accountable to the voters?” Romney asked. “Why does ‘flexibility’ with foreign leaders require less accountability to the American people?”

“President Obama has made clear his intentions on missile defense both in word and deed,” a source close to the Obama campaign hit back. “This administration has a strong national security record that illustrates an understanding of today’s military and security threats.”

The source continued, “The real question is what kind of commander-in-chief Mitt Romney would be when he still believes Russia is our number one foe, showing a real lack of understanding of what the world looks like today.”

Following Obama’s exchange with Medvedev last week, Romney had criticized Obama for the assurances he had offered “our number one geopolitical foe.” Obama personally increased the heat on Romney Tuesday, for the first time attacking the GOP challenger directly by name.