* China FX regulator calls U.S. to act responsibly on debt, dlr
* Says China cannot use reserves to buy too much gold, oil (Adds details)
BEIJING, July 20 China pressed the United States to take "responsible" measures to boost market confidence in the dollar and U.S. government debt on Wednesday, underscoring investor worries that Washington could default on its debt.
The urging from China's currency regulator came as U.S. leaders tried to hammer out an 11th-hour deal to raise a $14.3 trillion debt ceiling for the United States before it runs out of money to cover all its bills on Aug. 2.
"We hope the U.S. government will take responsible policies and measures to boost global financial market confidence and respect and protect the interests of investors," the State Administration of Foreign Exchange said.
The remarks, published on its website, were carried as a response to queries on whether Beijing will cut its investment in U.S. Treasuries following through from rating agencies saying they may cut the United States' credit rating.
The agency, which manages China's $3.2 trillion in foreign exchange reserves, the world's largest, said its buying and selling of Treasuries were part of normal investment operations.
Due to the size of China's reserves, Beijing has few choices but to invest the bulk of the stash in U.S. Treasuries, by far the world's biggest and most liquid asset class.
About two-thirds of China's reserves are estimated to be invested in dollar assets, ranking Beijing as the biggest creditor to the United States.
While China is keen to cut its reliance on the dollar by investing its reserves in other assets, its currency regulator acknowledged the crucial role of Treasuries by saying it is "an important investment product for both U.S. domestic and international institutional investors".
The currency regulator also argued it cannot invest too much of China's reserves in commodities such as oil, gold and silver these markets are too volatile and small.
"Chinese companies and households consume a large amount of gold and crude oil," it said.
"If we use much of our foreign exchange reserves to invest in such areas, we could push up market prices, which may affect our people's consumption and economic development."
For a full translation of the agency's comments, please click on
(Reporting by Zhou Xin and Koh Gui Qing; Editing by Jacqueline Wong)