Rice Calls for China-Taiwan Talks
China views Taiwan as its own territory and has often threatened to invade.
Ms Rice, who is on a four-nation tour of Asia, is now in Thailand.
On Sunday, the secretary of state met Chinese President Hu Jintao , and called on China to contact Tibet's exiled Dalai Lama.
She said the Dalai Lama, who is Buddhist Tibet's exiled spiritual leader, posed no threat to China's territorial claim to the Himalayan territory.
Earlier this year, China passed a law effectively authorising the use of military action against Taiwan, although the government in Beijing has insisted there are no current plans to invade the territory.
"America's desire is that there be no unilateral changes to the status quo," Ms Rice said.
"We are concerned about the military balance, and China should do nothing militarily to provoke Taiwan."
Ms Rice praised China's efforts at "cross-straits" contact with Taiwan, but said future contacts should be with the elected government of Chen Shui-Bian, instead of opposition leaders.
Beijing has been accused of trying to isolate Mr Chen by speaking only to his opponents.
Taiwan split from China in 1949 as the Communist Party seized power on the mainland. Relations have been icy ever since, and China pressures most of the world not to recognise Taiwan's claim of independence.
In Thailand, Ms Rice is to visit a school being re-built following December's Indian Ocean tsunami and other reconstruction projects. She will also meet the Thai prime minister, Thaksin Shinawatra.
After Thailand, Ms Rice will travel to Japan and South Korea.