U.S. Treasury Secretary Timothy Geithner has arrived in Beijing for talks aimed at convincing Chinese officials to support U.S. sanctions against Iran's oil industry.

Geithner is seeking Chinese cooperation with recently enacted U.S. legislation that calls for sanctions against financial institutions that deal with Iran's Central Bank, which is its main clearinghouse for oil exports.

China – Iran's top oil customer – has repeatedly opposed the U.S. sanctions, saying they are unilateral and will not help convince Iran to abandon its controversial nuclear program.

On Monday, Chinese Deputy Foreign Minster Cui Tiankai defended Iranian oil imports, saying Chinese-Iran trade relations have “nothing to do with the nuclear issue.”

The U.S. Treasury Department says Geithner will also discuss ways to promote global economic growth, and will bring up what it called measures to “level the playing field for U.S. workers and firms.”

U.S. officials have long contended that China's currency, the yuan, is substantially undervalued. The U.S. says that gives Chinese exporters an unfair advantage and has led to a wide U.S. trade deficit with China.

Geithner's two-day visit is beginning Tuesday with a dinner meeting with Chinese Vice Premier Wang Qishan. He will meet Wednesday with Premier Wen Jiabao, Vice President Xi Jinping and Executive Vice Premier Li Keqiang.

On Thursday Geithner travels to Japan, which relies on Iranian oil for 10 percent of its energy supply.

In November, the United States, Britain and Canada imposed additional sanctions on Iran, citing evidence that Iran is pursuing nuclear weapons. Tehran denies the claim, saying its nuclear program is intended for peaceful purposes.