A senior Chinese official says it's unacceptable for U.S. lawmakers to threaten to slap punitive tariffs on Chinese goods if Beijing doesn't change its currency policy.

Vice Commerce Minister Zhong Shan told reporters Wednesday that China will not "succumb to foreign pressures to adjust our exchange rate."

U.S. lawmakers say China's undervalued currency gives Chinese exporters an unfair trade advantage and costs millions of Americans their jobs.

The dispute threatens a relationship crucial to settling a raft of global problems.

Zhong says the stability of China's yuan benefits the world economy. He would not say when the yuan's value might appreciate. Zhong is in Washington to try to ease trade tension over China's currency.