RENO, Nev. -- Republican presidential candidate Mitt Romney on Tuesday called for an independent investigation into claims the White House had leaked national security information for President Barack Obama's political gain, part of a searing speech that marked a wholesale indictment of the Democrat's foreign policy.
In a race that has so far focused almost entirely on the sluggish economy, Romney also critiqued Obama's handling of Iran's nuclear threat, the violence in Syria and relations with Israel during a speech to the Veterans of Foreign Wars convention.
In his first foreign policy speech since emerging as the likely Republican presidential nominee, Romney accused Obama of putting politics over national security, a serious charge that went straight at a policy area where national polls show the president with the edge.
The turn also was a reminder that the increasingly biting campaign, which paused over the weekend in deference to the deadly movie theater shooting in Colorado, was on again in earnest.
"This conduct is contemptible," Romney said of the leaks of classified information. "It betrays our national interest. It compromises our men and women in the field. And it demands a full and prompt investigation by a special prosecutor, with explanation and consequence."
Attorney General Eric Holder has appointed two federal prosecutors to get to the bottom of the leaks, but Romney suggested that wasn't good enough. The White House has rejected calls for a special prosecutor, saying there is no need for one.
Romney stopped short of accusing Obama specifically of leaking information that includes details of the mission that killed Osama bin Laden last year. He made the charge as he prepared to embark later Tuesday on a trip to Great Britain, Israel and Poland and meetings with a host of foreign leaders.
Obama has strongly rejected the leak accusations that, until Tuesday, had been contained to Republicans in Congress.
During a news conference last month, he called the accusations "offensive" and "wrong."
White House spokesman Jay Carney responded Tuesday by saying Obama "feels extremely strongly about this" and noting Holder's appointment of the two federal prosecutors to investigate.
"The president has made abundantly clear that he has no tolerance for leaks and he thinks leaks are damaging to our national security interests," Carney said.
Reflecting the campaign's recent attention to veterans, Obama added a visit Tuesday with some of them to his fundraising schedule in Portland, Ore.
Obama slid into a blue vinyl booth with three middle-aged veterans who were among the lunchtime crowd at The Gateway Breakfast House. The conversation turned quickly to veterans care, including those who live in rural areas.
Campaign spokesman Ben LaBolt said Romney was resorting to "cheap attacks" on the president "that lack credibility."
Romney referenced comments from Sen. Dianne Feinstein, who said Monday that the White House appeared to be behind some leaks of classified information. The California Democrat, who chairs the Senate Intelligence Committee, said she was convinced Obama himself did not didn't leak secret information.
It's been a simmering Republican complaint, quelled little by Holder's action, in response to leaks about the bin Laden raid, as well as U.S. involvement in cyberattacks on Iran and about an al-Qaida plot to bomb a U.S.-bound airliner.
Feinstein said Tuesday she was "disturbed by these leaks."
"I regret that my remarks are being used to impugn President Obama or his commitment to protecting national security secrets," she said in a statement.
Romney, a former Massachusetts governor with a business background, has for months aggressively raked Obama's stewardship of the economy. Polls consistently have shown voters see Romney as better able to handle it.
But Romney has been unable to cut into Obama's edge on national security issues. The administration's counterterrorism fight against al-Qaida and especially the killing of bin Laden has undercut the label Republicans have long attached to Democrats as soft on defense.
Romney called for a total cessation of uranium enrichment in Iran, and proposed tying foreign aid to Egypt to peaceful relations between Egypt and Israel.
He called for strict enforcement of sanctions against Iran and pledged to use "every means necessary to protect ourselves and the region."
But the speech was more criticism than proposition.
Romney said Obama had alienated Israel and other key U.S. allies such as Poland and the Czech Republic.
He derided as politically motivated Obama's candid comment to the Russian president that he would have more flexibility to deal with Russia after the election.
Vice President Joe Biden hit Romney for "reflexively" criticizing Obama's policies without offering alternatives.
"When he does venture a position, it's a safe bet that he previously took exactly the opposite position and will probably change his mind again and land in the wrong place -- far out of the mainstream," Biden said in a statement.
Romney also suggested that politics is driving Obama's push for defense cuts and warned the spending reductions would weaken the military. "Strategy is not driving President Obama's massive defense cuts," Romney said.
The automatic, across-the-board cuts of $1.2 trillion to defense and domestic programs are slated to begin on Jan. 2 unless Congress comes up with a plan to avoid them. They were set in motion after a bipartisan congressional "supercommittee" failed to come up with an equivalent amount in cuts.
Republicans have tried to pin the looming defense cuts on Obama, but GOP members in the House and Senate voted for the reductions last August as part of a far-reaching bill that raised the nation's borrowing authority and implemented cuts to reduce the growing federal deficit.
Obama made that point in his speech to the same group on Monday.
"There are a number of Republicans in Congress who don't want you to know that most of them voted for these cuts," Obama said. "Now they're trying to wriggle out of what they agreed to."
It's also a local campaign issue in competitive states such as Virginia and Florida, states with a large military civilian workforce.
But the criticism of Obama on military spending could also help Romney, who faces scrutiny in these states for proposing a 10 percent cut in the federal workforce that would affect military and defense jobs.
A NBC/Wall Street Journal poll published Tuesday showed Obama is seen as a better commander in chief, 45 percent to 35 percent. Last week, a CBS News/New York Times poll found 47 percent of voters said Obama would do a better job handling foreign policy, while 40 percent chose Romney.