Vietnam is extending a runway on an island it claims in the South China Sea in apparent response to China’s building of military facilities on artificial islands in the region, a U.S. think tank reported.

Satellite images taken this month showed Vietnam had lengthened its runway on Spratly Island from less than 2,500 feet (760 meters) to more than 3,300 feet (1 km), Washington’s Asia Maritime Transparency Initiative said on Thursday.

AMTI, a project of the Center for Strategic and International Studies think tank, said continued reclamation work would likely mean the runway was extended to more than 4,000 feet (1.2 km).

It said the upgraded runway would be able to accommodate maritime surveillance aircraft and transport planes, as well as combat aircraft.

The report said Vietnam had added about 57 acres (23 hectares) of land to Spratly Island in recent years, but its reclamation work remained modest by Chinese standards.

http://www.reuters.com/article/us-southchinasea-vietnam-idUSKBN13C2TH