Secretary of State Condoleezza Rice (search) on Sunday sought further help from China in getting North Korea back to nuclear disarmament talks and aired U.S. concerns about Beijing's bellicose rhetoric on Taiwan (search).

As part of a two-day visit to the Chinese capital, Rice took time to attend a Palm Sunday (search) church service at one of the city's few state-sanctioned churches. Although Rice has said the United States is not satisfied with the extent of religious freedom in communist China, she did not make that point explicit on Sunday.

China was the final stop on a weeklong tour of Asian capitals for Rice, and it was the most delicate for America's new chief diplomat. President Bush's second-term pledge to carry democratic ideals around the globe has met with suspicion in China, where government control remains a strong and constant fact of daily life.

The United States is cooperating with China on several fronts, including six-nation talks over North Korea's nuclear program. But Washington has complaints about China's record on human rights, its treatment of dissidents and the rampant piracy of movies, books and other intellectual software.

"There is a lot we can do that is constructive with China, but of course we have our differences," Rice said before flying from South Korea to China.

Rice also suggested that European governments would be acting irresponsibly if they sold sophisticated weaponry to China that might one day be used against U.S. forces in the Pacific.

"It is the United States, not Europe, that is defending the Pacific," Rice said, adding that South Korea and Japan are contributing resources to keep the Asia-Pacific region stable.

The European Union soon may lift an arms embargo on China that was imposed after the 1989 crackdown on pro-democracy protesters in Tiananmen Square.

Lifting the embargo would allow sale of technology and weapons that China badly wants to modernize its military. China recently has gone on a military spending spree that Rice said concerns the United States.

China passed a law this month codifying its intention to use military force against Taiwan should the island declare formal independence. Under its complicated policy on China and Taiwan, The United States is obligated to defend Taiwan against an attack from the mainland.

In Washington, the Joint Chiefs of Staff chairman, Gen. Richard Myers, said, "Clearly it's not in anybody's interest to settle this by force."

The United States wants China to use its leverage on North Korea, but Washington's leverage over China is limited. Rice pressed the North Korean nuclear issue in a meeting with Chinese President Hu Jintao, a State Department official said.

The United States, Russia, Japan, South Korea and China began a joint diplomatic effort with North Korea last year aimed at persuading the North to give up its nuclear program.

But those talks, hosted by China, stalled in September. The North Koreans pulled out, has refused to return to the discussions and announced last month that it has built at least one nuclear weapon.

A Bush administration official said Rice had preliminary discussions this past week about a fallback position if the six-way talks fail.

"During the trip there was some understanding among others that this can't go on forever," although there is no deadline for declaring the talks dead, said the official, who spoke on condition of anonymity.

The United States has proposed incentives that include potential help with North Korea's energy crunch if the North abandons up a weapons program.

On her trip, Rice has tried not to provoke the volatile North Korean government. She has offered repeated assurances that the United States has no intention of attacking and that Washington recognizes that North Korea is a sovereign state.

Yet the secretary also toured a mountainside bunker that would be the headquarters should war break out between South Korea and North Korea. The United States has nearly 33,000 troops in South Korea to defend against an attack from the North.

"Make no mistake about it, I don't think North Korea poses a threat to South Korea today," Myers, the Joint Chiefs chairman, told NBC's "Meet the Press."

"They know that if they were to start any conflict on that peninsula, that would be the end of their regime," Myers said. "They would lose. And they know that, and we're very confident about that."