Washington (CNN) -- The administration's top counterterrorism adviser said Friday that the al Qaeda group based in Yemen poses a greater threat to Americans than Osama bin Laden's group based in Pakistan.

John Brennan, assistant to the president for homeland security and counterterrorism, said the Yemen-based group, al Qaeda in the Arabian Peninsula, is "increasingly active" in reaching out to find terrorist recruits, even in the United States.

"Al Qaeda in the Arabian Peninsula is now the most operationally active node of the al Qaeda network," Brennan said during a forum at the Carnegie Endowment for International Peace.

"The ranks of al Qaeda have been bolstered by members with ties to the West, or with American citizenship, such as Anwar al-Awlaki," he said. "Indeed, al Qaeda is seeking to attract not just Westerners or Americans overseas, but Americans inside the United States."

Al-Awlaki is the American-born Muslim who moved to Yemen and has become a key figure in AQAP. He has been linked to the suspect in the Fort Hood massacre of 13 people last year, as well as the suspect in last year's Christmas Day "underwear bombing" attempt in which a man allegedly tried to detonate an explosive device sewn into his underwear as his flight headed toward Detroit.

Brennan's remarks came a day after the release of the annual Afghanistan/Pakistan review and President Barack Obama's outline of his view of the threat posed by al Qaeda from its Pakistan base.

"It will take time to ultimately defeat al Qaeda, and it remains a ruthless and resilient enemy bent on attacking our country," Obama said Thursday.

But it's been al Qaeda in the Arabian Peninsula that has been behind most recent terror plots inside the United States.

Yemen tightened security at all of its airports last month in the aftermath of a plot to send bombs from Yemen to the United States hidden inside printer parts, the country's National Civil Aviation Security Committee said. AQAP claimed responsibility for the failed bomb plots.

America's top ally in the battle against AQAP is the central government of Yemen. Brennan described his meetings with Yemeni President Ali Abdullah Saleh as "animated."

Last winter, the U.S. Department of Defense announced plans to boost the military aid it is sending Yemen from $70 million to $150 million. And a recently leaked diplomatic cable showed Yemen's president was willing to deceive the public about air strikes against al Qaeda sites.

"Saleh lamented the use of cruise missiles that are "not very accurate" and welcomed the use of aircraft-deployed precision-guided bombs instead. 'We'll continue saying the bombs are ours, not yours,' Saleh said," according to the leaked cable from January of this year.

Despite this incident, Brennan said, "the relationship between Washington and Sanaa (Yeman's capital) is, at times, marked by differences of view, tension, and even strong frustration by each side."

But he went on to say that's a good thing: "That is the hallmark of true friendship -- not telling the other what they want to hear, but telling the other what they need to hear."

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Richardson presents proposals to 
North Korea aimed at easing crisis

New Mexico Gov. Bill Richardson is welcomed by an unidentified North Korean official upon his arrival at the Pyongyang Airport on December 16.

Pyongyang, North Korea (CNN) -- New Mexico Gov. Bill Richardson provided North Korea with a series of proposals Saturday in what he described as a "good meeting" with the country's chief nuclear negotiator -- part of a series of meetings on a four-day trip aimed at easing tensions in the region.

Richardson declined to provide details about his proposals, and it was unclear how North Korea responded to them.

His meeting with the North's chief nuclear negotiator Kim Gye Gwan came as South Korea announced that scheduled military drills likely would not be held this weeked due to an adverse weather forecast.

The drills will be held only if the weather improves in the areas surrounding Yeonpyeong Island, South Korea's Joint Chiefs of Staff said.

The planned drills sparked harsh reaction from North Korea, which warned that it would launch a military strike against the South if Seoul goes ahead with the live-fire exercises, the North's state-run Korean Central News Agency reported.

The drills, originally scheduled to take place between December 18 and 21, will likely be pushed back a day or two, South Korea's official Yonhap News Agency reported.

"Kim Gye Gwan basically told Richardson he didn't sleep last night because of the tensions on the Korean peninsula. It's a very serious situation," said CNN's Wolf Blitzer, who is traveling with the governor in North Korea.

Richardson told Blitzer that he made a series of proposals in Saturday's meeting "that he thinks if implemented could ease the crisis, which by all accounts right now is the most serious crisis on the Korean peninsula since the 1953 armistice which ended the Korean war."

Richardson said earlier Saturday he was concerned about escalating tensions on the Korean peninsula, where he is urging "maximum" restraint around the planned military exercises.

"This is a tinderbox," he told Blitzer. "Right now, my objective is to say -- tamp things down."

Both Koreas have traded tough talk and conducted aggressive military drills in the weeks after North Korea shelled a South Korean island last month.

Richardson, a former U.N. ambassador, arrived in North Korea Thursday on a four-day trip he hopes will help to ease tensions in the region.

"Let's cool things down. No response. Let the exercises take place," said Richardson, who added: "On all sides, I'm urging restraint."

He met with a vice minister of North Korea's Ministry of Foreign Affairs on Friday and is scheduled to meet with a top North Korean general Sunday.

"Meeting a top military person is significant," said Richardson, who has hosted a North Korean delegation in New Mexico in the past. "Hopefully, we can keep things from firing up."

Richardson is not in North Korea as an official U.S. envoy.

Tensions mounted between the Koreas on November 23, when North Korea shelled Yeonpyeong Island, which lies in South Korean territory. The attack killed two marines and two civilians and injured 18 people.

The North has accused the South of provoking the attack because shells from a South Korean military drill landed in the North's waters.

Last month's attack was the first direct artillery assault on South Korea since 1953, when an armistice ended fighting.

The U.S. military has said it is concerned that South Korea's scheduled exercises could spark an uncontrollable clash with the North, but the State Department said the exercises are not meant to be threatening or provocative.