A senior government economist says China's trade surplus for the first half of this year is expected to top US$100 billion, a state news agency said Monday, amid calls by U.S. lawmakers for punitive action against Beijing.

Total trade for the first half is expected to top US$1 trillion, up 24 percent from the year-earlier period, the Xinhua News Agency said, citing Yao Jingyuan, chief economist for the National Bureau of Statistics.

"The trade surplus reached US$85.7 billion in January-May, and for the first half of the year will exceed US$100 billion," Xinhua said, citing Yao.

American lawmakers are calling for legislation to impose higher tariffs on imports of Chinese goods or take other punitive steps if Beijing fails to ease currency controls that some say are helping to swell the surplus.

China reported a global trade surplus last year of US$177.5 billion.

U.S. critics of China's trade record blame its growing surpluses for the loss of American manufacturing jobs.

The growing gap also is causing financial problems for Beijing, which is forced to drain billions of dollars a month from the economy to reduce pressure for prices to rise.

The government says it is not actively pursuing a surplus and has taken steps to slow exports, including revoking rebates of value-added taxes to exporters.