The United States is worried by the lack of transparency about China's first aircraft carrier, which made its maiden voyage on Wednesday, a U.S. State Department spokeswoman said.
"We want to see more transparency. We would welcome any kind of explanation that China would like to give for needing this kind of equipment," Victoria Nuland said.
"This is part of our larger concern that China is not as transparent as other countries. It's not as transparent as the United States about its military acquisitions, about its military budget," she added. "And this causes concern."
China bought the Admiral Kuznetsov-class aircraft carrier, was originally build in the Soviet Union and named Varyag, from Ukraine for $20 million in 1998. Before being sold, the ship was disarmed and its engines were removed.
The 1,000-feet vessel is designed to carry 26 planes and 24 helicopters and be equipped with Soviet-designed AK-630 and CADS-N-1 Kashtan close-in weapon systems, P-700 Granit anti-ship cruise missiles, Tor short-range surface-to-air missile systems and UDAV-1 anti-submarine weapon systems.