WASHINGTON (AP) _ President Bush and Chinese President Hu Jintao pledged cooperation in reining in the nuclear ambitions of Iran and North Korea and resolving troubling trade disputes of their own Thursday, but they made little measurable headway in a pomp-filled summit that was infiltrated by a screaming protester.

In a half-day of talks, the watchwords were candor and discussion _ not agreement and announcement.

The discussions touched on American concerns about Beijing's human rights record and the global energy impact of the communist giant's rapidly expanding economy, as well as China's sensitivity over the status of Taiwan.

White House officials stressed the growing sophistication of U.S.-Chinese relations, and the increased personal familiarity between Bush and Hu after five meetings in less than a year, as one of the summit's achievements.

``We have made progress in building a relationship that is candid and cooperative,'' Bush said.

In opening remarks after a majestic arrival ceremony, Hu made clear he did not intend to do much more than reiterate past promises _ and he did not. ``I have come to enhance dialogues,'' said Hu from a sun-splashed South Lawn podium, speaking in Chinese that was translated.

Hu had barely begun his speech when a woman began pleading with Bush to stop the Chinese president from persecuting the Falun Gong, a banned religious movement that accuses the Chinese government of torturing and killing its followers.

Bush quietly encouraged his guest to resume talking _ ``You're OK,'' he said _ as the woman's shouts continued even as Secret Service agents removed her. Hoping to defuse any tensions over the embarrassing incident, Bush later opened the leaders' Oval Office meetings with a personal apology.

``This was unfortunate. I'm sorry it happened,'' the president told his guest, according to the White House's top Asian affairs expert, Dennis Wilder. Terming it only ``a momentary blip,'' Wilder said Hu graciously dropped the matter.

The woman's complaints were no different from those that were voiced all day outside the White House gates _ and within earshot of those inside.

Falun Gong orchestrated loud protests that drew hundreds to the streets around the White House, only steps from the Blair House government guest quarters where Hu was staying. They banged gongs, waved American and Chinese flags and held banners denouncing Hu as a ``Chinese dictator'' responsible for genocide and other ``crimes in Chinese labor camps and prisons.''

Their chants could be heard during the quieter moments of the arrival ceremony. And as Bush feted Hu and nearly 200 others with a formal lunch of Alaskan halibut and fine wine in the pink-and-gold-adorned East Room, the demonstrators were visible through open curtains.

The choreography of the day had been planned to give the protocol-conscious Chinese their due as a rising world power without affording Hu the ultimate perk of a ``state visit.'' For instance, Hu was greeted with the full 21-gun salute, a traditional U.S. military honor guard in colonial dress and a formal luncheon. But he did not rate a glitzy black-tie state dinner, or even the honor of his country's flags flying beside American ones from the lampposts around the White House compound.

One gaffe during the elaborate arrival ceremony threatened the delicate balancing act. Before the playing of the two countries' national anthems, a White House announcer referred to China as the ``Republic of China,'' the formal name of Taiwan.

Beijing claims sovereignty over the self-governing island, which split from the mainland when communists took over in 1949, and threatens to use force should Taiwan move toward formal independence. With the United States legally bound to supply Taiwan with the military hardware needed to defend the island but officially not in support of independence, Hu indicated that the issue was a major item of discussion for him with Bush.

During a dinner sponsored by U.S. business interests Thursday night, Hu said China would never allow forces to split Taiwan from China in any way.

Addressing critics of China's human rights record, Hu told the crowd of Washington luminaries that ``China takes human rights seriously.''

White House officials pronounced the summit a success. But on issue after issue, Bush pressed Hu but came up without any new concrete promises.

The United States wants a faster revaluation of China's tightly controlled currency, which is artificially low so that China's goods are cheaper and U.S. products have a harder time competing with them. A major irritant in the relationship, it is considered the key to reducing America's record $202 billion trade deficit with China.

Hu offered general promises. ``We have taken measures and we will continue to take steps to properly resolve the issue,'' he said.

Bush put the best face on it, saying ``He recognizes that a trade deficit with the United States, as substantial as it is, is unsustainable.''

Wilder praised Hu for publicly committing to structural reforms that would eventually begin to close the trade gap, but acknowledged the Chinese moves so far to revalue its currency are ``not nearly enough.'' Still, the day's rhetoric was likely to do little to cool calls in Congress for punitive tariffs on Chinese products.

``Good words need to be followed by concrete action,'' said Sen. Charles Grassley, R-Iowa., the author of sanctions legislation. ``If not, that'll only increase the frustration in Congress that China's not living up to its commitments.''

On Iran, Hu stressed that the standoff over Iran's nuclear program should be resolved ``through diplomatic negotiation.'' Bush had hoped to bring China closer to the U.S. and European view that Tehran should face sanctions if it does not comply with demands that it halt uranium enrichment.

The president also raised human rights concerns with Hu, including a list of specific people previously presented to Hu in September and the case of a North Korean defector who was returned by China. Bush got little response, Wilder said.

The two leaders did agree to take questions from the media, and Wilder noted with some surprise that Hu, when asked about the pace of democratic reform in China, said ``if there is no democracy, there will be no modernization.''

Bush and Hu seemed most in unison on the topic of drawing North Korea back to six-nation talks aimed at halting its nuclear weapons program, and the leaders chose to ignore protocol to sit together at lunch to discuss it further. Bush asked Hu to use his country's ``considerable influence'' with Pyongyang to spur progress. Hu expressed his frustration with North Korea and committed to ``doing his utmost'' to help, Wilder said.