MOSCOW - Russian President Vladimir Putin said today that Mitt Romney's characterization of Moscow as the United States' "number one geopolitical foe" has actually helped Russia.

The Russian leader said Romney's comments strengthened his resolve to oppose NATO's plan for a missile defense shield in Eastern Europe, a system Russia believes will degrade its nuclear deterrent. The U.S. insists the system is aimed at Iran, not Russia.

"I'm grateful to him (Romney) for formulating his stance so clearly because he has once again proven the correctness of our approach to missile defense problems," Putin told reporters, according to the Russian news agency RIA Novosti.

"The most important thing for us is that even if he doesn't win now, he or a person with similar views may come to power in four years. We must take that into consideration while dealing with security issues for a long perspective," he said, speaking after a meeting with Serbian President Tomislav Nikolic, according to Interfax news agency.

Putin also waded into the U.S. election in an interview last week with state-controlled Russia Today television. Putin called President Obama "a very honest man" and said after their meeting at the G20 in Los Cabos, Mexico, he believed he could strike a missile defense deal with him, saying Obama's willingness to deal appeared "quite sincere."

Obama caused some controversy when he was caught on an open microphone at a summit in South Korea in March telling then-Russian President Dmitri Medvedev he would have more room to negotiate missile defense after the November presidential election.

During the same interview with Russia Today last week, Putin said he could work with Romney, but also expressed concerns about the GOP nominee, or someone with similar views, taking over the reins of the missile defense shield.

"In that case, the system will definitely be directed at Russia," he said, according to a transcript posted on Putin's official website.

After Romney's "geopolitical foe" comment last spring, Medvedev chided him for being stuck in the 1970s.