China said on Tuesday that a U.S. plan to deploy a missile defense shield in Eastern Europe may cause new weapon proliferation problems.

"China has always maintained that missile defense affects the strategic balance and international stability, is not conducive to mutual trust between major powers and may cause new proliferation problems," said Chinese Foreign Ministry spokeswoman Jiang Yu.

"The United States' intention to deploy a missile defense system in Eastern Europe has drawn considerable attention and some countries are very concerned," Jiang told a regular press conference.

The United States plans to deploy missile interceptors in Poland and radar units in the Czech Republic as part of a project to extend its missile defense system in Europe. Russia has voiced strong opposition to the deployment.

"We have the same attitude in regard to missile defense systems proposed by the U.S. and Japan and trust the parties concerned will act with discretion," said Jiang.