PORTSMOUTH, N.H. - Gov. Christie called for bolstering the military and American intelligence efforts as he laid out a foreign policy agenda Monday in his third trip this month to the early presidential primary state of New Hampshire.

Warning of threats posed by Iran, Russia, and "the sinister black flag of ISIS," the Republican governor sought to draw a contrast with President Obama, accusing the Democratic president of failing to articulate clear policies abroad and worsening relationships with allies.

"His unwillingness to stand behind his own words has made America weaker and less reliable in the world," Christie said. "He has damaged the credibility of the American presidency."

Christie also took a hard line in favor of government intelligence gathering while touting his experience using the Patriot Act as U.S. attorney for New Jersey.

He described former National Security Agency contractor Edward Snowden, who leaked classified records, as a "criminal," and denounced "civil liberties extremists."

"When it comes to terrorism, our government is not the enemy," Christie said, calling for tougher laws, including the extension of the Patriot Act provision that has formed the basis of the NSA's bulk collection of phone records.

That position puts him at odds with some Republicans, including presidential candidate Kentucky Sen. Rand Paul, who oppose the NSA program. The House last week passed legislation to prohibit the government's bulk collection of telephone records.

And he advocated greater investment in the military, criticizing the cuts imposed by sequestration. He said the Army and Marines should not be reduced to levels below their pre-Sept. 11 strength, calling for 500,000 active-duty soldiers and 185,000 active-duty Marines.

The Army had 510,000 active-duty soldiers in fiscal year 2014 and was due to decline to 490,000 by the end of the current fiscal year, according to the Heritage Foundation. Last year, there were 188,800 active-duty Marines, a figure expected to decline to 182,100 by fiscal year's end.

Christie said the Navy needed more ships - a total of 350 - and the Air Force modernized equipment and a total force of 6,000 aircraft. "We need to give our men and women in uniform the resources they need to get the job done," Christie said.

The speech - Christie's third policy address since April - followed a week of attention to the war in Iraq spurred by former Florida Gov. Jeb Bush's remark that knowing what is known now, he would have authorized the war his brother started. Bush said he misheard the question and has since said he made a mistake in responding.

"The timing is fortuitous" for Christie to focus on foreign policy, given that "the perceived front-runner stumbled a bit in this area," said Tom Rath, a longtime GOP strategist in New Hampshire.

Noting New Hampshire's defense industry, Rath said a policy approach backing "engagement around the world" would resonate with the state's Republicans.

While New Hampshire voters aren't "war-loving," Rath said, "they tend to be muscular."

Christie did not address what one expert described as a key structural problem in the defense budget: increases in pay and benefits for military personnel since 2001.

"Especially in the sequestration era, pay and benefits are squeezing out" other defense spending, said Stephen D. Biddle, adjunct senior fellow for defense policy at the Council on Foreign Relations.

"If you want a big Navy and a big Army" with modernized equipment, "and you're going to continue pay raises, you're going to end up with a huge defense budget," Biddle said.

He said the size of the military Christie had proposed did not appear to be enough to wage a counterinsurgency in Syria. But assisting allies in medium-size conventional wars "doesn't require a particularly big army," Biddle said, describing the force outlined by Christie's plan as "stuck in the middle."

Christie's speech was "very similar to any other Republican foreign policy speech you would see," said Daniel Drezner, an international politics professor at the Fletcher School at Tufts University. "The world is on fire. America is in retreat. This is the fault of the current president, who has appeased adversaries and alienated allies."

But Christie's discussion of intelligence - and highlighting his role as U.S. attorney - was "a clever way to point out he has some experience beyond governor of New Jersey," Drezner said.

A recent NBC News/Wall Street Journal poll found that among Republican primary voters nationally, the top issue for the federal government to address was national security and terrorism, at 27 percent.

Andy Smith, director of the University of New Hampshire Survey Center, said Republicans would likely try to use foreign policy to attack Democratic former Secretary of State Hillary Rodham Clinton, as well as to differentiate among themselves.

At a town-hall-style meeting later Monday in Hudson, Christie described how as U.S. attorney, he had brought "two major terrorism cases," including charges against "six radical Islamic terrorists" in a plot targeting Fort Dix.

"Part of why Sept. 11 happened was because we did not have the intelligence we needed to prevent these attacks," Christie said at a VFW hall, where people seated around tables asked a number of foreign-policy related questions.

Defending his position on intelligence, Christie said, "You can't enjoy your civil liberties if you're in a coffin."