China's military takeover of the South China Sea could grow after the construction of a third airstrip in the contested territory, Reuters reported Monday. The strip could accommodate most Chinese military aircraft, potentially giving Beijing greater access to maritime Southeast Asia.

Satellite photographs taken last week for Washington's Center for Strategic and International Studies (CSIS) think tank show construction on Mischief Reef, one of several artificial islands China has built in the Spratly archipelago. The construction includes a retaining wall roughly 3,000 meters long that matches similar developments by China on two other reefs, Subi and Fiery Cross, Greg Poling, director of CSIS' Asia Maritime Transparency Initiative, said. "Clearly, what we have seen is going to be a 3,000-meter airstrip, and we have seen some more work on what is clearly going to be some port facilities for ships," he told Reuters.

The construction comes as Chinese President Xi Jinping was scheduled to visit Washington this month. “This is a challenge for the White House,” Michael J. Green, a senior vice president at CSIS and former senior director for Asian affairs at the National Security Council under President George W. Bush, told the Washington Post. “How do they talk about this? Do they say, ‘Don’t militarize these islands,’ knowing that the Chinese will do it anyway? Do they say, ‘Don’t continue construction,’ when it’s obvious that it will continue anyway?”



China claims sovereignty over the entire South China Sea, while Vietnam, the Philippines, Brunei, Malaysia and Taiwan have rival claims. U.S. officials have warned against China taking new territory in that area of ocean. "China's stated intentions with its program, and continued construction, will not reduce tensions or lead to a meaningful diplomatic solution," Commander Bill Urban, a spokesman for the U.S. Defense Department, told Reuters.

China's Foreign Ministry spokesman Hong Lei said Monday that China had "indisputable sovereignty" over the Spratly Islands, which allowed it to establish military facilities there.