(Adds U.S. comment, paragraphs 2-3 and 10-12)
BEIJING/WASHINGTON, March 24 (Reuters) - China wants a clear explanation from Washington over reports that the U.S. National Security Agency infiltrated servers at the headquarters of telecoms giant Huawei Technologies Co, a Chinese foreign ministry spokesman said on Monday.
Chinese President Xi Jinping raised the reports in a meeting with U.S. President Barack Obama on the sidelines of a nuclear summit in The Hague and was told that the United States did not spy to gain commercial advantage, White House deputy national security adviser Ben Rhodes said.
"We don't share information with our companies," Rhodes told reporters in Washington.
Chinese Foreign Ministry spokesman Hong Lei said China was "extremely concerned" about the spying allegations.
"Recently, the international media has put out a lot of reports about the eavesdropping, surveillance and stealing of secrets by the United States of other countries, including China," he told a regular briefing.
"China has already lodged many complaints with the United States about this. We demand that the United States makes a clear explanation and stop such acts."
Questions over cyber-espionage have cast a shadow over China-U.S. ties, with each side accusing the other of spying.
On Saturday, The New York Times and German magazine Der Spiegel published articles on information about Huawei contained in classified documents that were provided to journalists by former NSA contractor Edward Snowden.
Der Spiegel also reported that the NSA was targeting China's political leadership, including former President Hu Jintao and the trade and foreign ministries.
U.S. State Department spokeswoman Marie Harf said she could not comment on specific operations in specific countries, but all U.S. intelligence activity was required by law to be "focused on the national security needs of our country."
"We collect signals intelligence exclusively where there is a foreign intelligence or counter-intelligence purpose," she told a regular news briefing.
"In other words, we don't collect these things to give U.S. companies economic advantage." (Reporting by Ben Blanchard in Beijing and David Brunnstrom and Jeff Mason in Washington; Writing by Megha Rajagopalan; Editing by Clarence Fernandez and Grant McCool)