FAIRFAX, Virginia (Reuters) - Republican presidential candidate Mitt Romney criticized President Barack Obama's handling of foreign policy on Thursday after four Americans were killed in Libya, saying the United States seems at the mercy of world events.
Romney made a case for a stronger U.S. military at a campaign rally in northern Virginia, an area that could play a deciding role in who wins the November 6 presidential election.
But the former governor of Massachusetts stopped short of repeating charges that Obama is apologizing to America's enemies.
"As we watch the world today, sometimes it seems that we're at the mercy of events, instead of shaping events," he said in Fairfax, a suburb of Washington, D.C.
Romney has come under fire from Democrats, pundits and some Republicans for criticizing the Obama administration's initial response to demonstrators at U.S. diplomatic missions in Benghazi, Libya, and Cairo.
Romney on Wednesday denounced the U.S. Embassy in Cairo for criticizing an anti-Islam film that enraged protesters who scaled the embassy's walls. The U.S. ambassador to Libya and three other Americans were killed when assailants attacked the consulate in Benghazi during a protest against the film.
Critics say Romney was too quick to inject election-year politics into a U.S. foreign policy crisis and that he got the timeline of the embassy incident wrong.
At the Fairfax event, Romney did not repeat his line of attack but he has shown no sign of backing away.
As he paid homage to the four Americans slain in Libya, a heckler interrupted Romney.
"Why are you politicizing Libya?" the man shouted, according to audio recorded by a television pool camera.
Romney said he had wanted to pause the campaign event for a moment of silence for the victims but "one gentleman doesn't want to be silent so we're going to keep on going."
The crowd of Romney supporters shouted down the heckler with chants of "USA" and he was escorted out. The Republican paid tribute to the four Americans, including Ambassador Christopher Stevens, saying, "What a tragedy to lose such wonderful people."
Romney accused Obama of instigating some big cuts in the defense budget that will come into effect at year's end unless the president can negotiate a budget deal with Congress.
"A strong America is essential to shape events. And a strong America, by the way, depends on a strong military. We have to have a military second to none and that's so strong no one would ever think of testing it," he said.
Romney likely needs to win Virginia in order to defeat Obama and much depends on how northern Virginia votes. Many residents of the area are dependent on government jobs in Washington.
Editing By Alistair Bell and Bill Trott