North Korea's nuclear ambitions and China's increasingly tense relationship with Taiwan (search) will be among Secretary of State Condoleezza Rice's (search) topics in discussions with Asian leaders this week.

The trip, Rice's farthest afield since becoming the top U.S. diplomat in January, includes stops in India, on Tuesday, followed by stops in Pakistan, Afghanistan, South Korea, Japan and China (search).

The Bush administration said Monday that China's threat to use force to stop any Taiwanese move toward independence could increase tensions in the region.

"We view the adoption of the anti-secession law as unfortunate," said White House press secretary Scott McClellan. "It does not serve the purpose of peace and stability in the Taiwan Strait. We believe it runs counter to recent progress in cross-Strait relations."

China's parliament on Monday enacted a law authorizing force if Taiwan pursues formal independence from mainland China.

"We have said to both parties that this is not helpful to have unilateral steps that raise tensions," Rice said Sunday on ABC's "This Week."

Rice noted that China is a partner in the diplomatic effort to end nuclear weapons development in North Korea (search) even as other aspects of U.S.-China relations remain troublesome.

"They are a rising force in international politics and there are both healthy aspects and troubling aspects to that," Rice said.

North Korea pulled out of six-way international arms talks last month and denounced the United States. Rice will use visits with South Korean and Chinese leaders to test the waters for a renewed diplomatic effort to persuade North Korea to give up its nuclear weapons program.

The Pyongyang government of Kim Jong Il (search) announced last month what the United States has long suspected: It has already built at least one nuclear weapon. In Seoul, Rice also will discuss the future of the large U.S. troop deployment in South Korea.

Some 33,000 U.S. troops are in South Korea as protection against any North Korean attack, but have also been an irritant to many South Koreans, especially younger people born after the Korean War. The Pentagon has announced plans to pull out about 12,000 troops, beginning this year.

The United States and South Korea will conduct joint military exercises this week amid the standoff over North Korea's nuclear weapons. Communist North Korea criticized the U.S. and South Korean militaries for the exercises and accused them of plotting a pre-emptive attack.

The 1950-53 Korean War ended in a cease-fire, not a peace treaty, leaving the two Koreas technically still at war.

North Korea test-fired a missile over Japan in 1998, demonstrating Pyongyang's ability to threaten both Japan and about 50,000 U.S. troops deployed there. Last year, North Korea tested an intercontinental ballistic missile engine capable of hitting Alaska.

Rice's trip begins in India, which is seeking closer defense ties with the United States, a stark contrast from the Cold War days when Washington considered New Delhi a Soviet ally. The United States and India recently completed the first phase of an agreement to cooperate in trade in high-technology, space, civilian nuclear safety and missile defense.

Three years ago, Washington dropped economic sanctions imposed on New Delhi (search) after it tested nuclear weapons in May 1998.

Rice has a more delicate diplomatic mission in Pakistan, a key ally in the war on terrorism but far from an ideal democracy. The United States wants Gen. Pervez Musharraf (search), who took power as president in a bloodless coup six years ago, to give up his post as head of the Army and institute additional democratic reforms.

Last week, State Department spokesman Adam Ereli said Musharraf "has taken and is taking steps to move in the right direction, and we will encourage him to continue in that vein."