"The United States should stop playing up the South China Sea issue, stop heightening tensions in the South China Sea and stop complicating disputes in the South China Sea," Hong Lei, a foreign ministry spokesman, said at a regular press briefing in Beijing.
"No country has the right to point fingers at" China's construction activities, he added.
The rebuke came after Obama met with Philippine President Benigno Aquino in Manila during the annual Asia-Pacific Economic Co-operation (APEC) gathering.
Beijing has turned a series of reefs and outcrops in disputed waters into artificial islands capable of hosting facilities with military purposes, alarming other claimants.
"We discussed the impact of China's land reclamation and construction activities on regional stability," Obama told reporters after meeting.
"We agree on the need for bold steps to lower tensions, including pledging to halt further reclamation, new construction, and militarisation of disputed areas in the South China Sea."
APEC members the Philippines, Vietnam, Malaysia, Brunei and Taiwan have rival claims to parts of the sea, which is believed to sit atop vast oil and gas resources.
Beijing claims nearly all of the South China Sea, even waters approaching the coasts of its Asian neighbors.
The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around 3,500,000 square kilometres (1,400,000 sq mi). The area's importance largely results from one-third of the world's shipping sailing through its waters and that it is believed to hold huge oil and gas reserves beneath its seabed.
It is located:
- south of mainland China, including the island of Taiwan, in
- east of Vietnam and Cambodia;
- west of the Philippines;
- east of the Malay peninsula and Sumatra, up to the Strait of
Malacca in the west and
- north of the Bangka–Belitung Islands and Borneo