The U.S. pressed Cambodia to address human rights abuses and increase transparency into China’s involvement at a coastal military base during talks Saturday at the U.S.-ASEAN Summit, the Whitehouse said.

President Joe Biden, in a sit down with Prime Minister Hun Sen, said improved bilateral relations depended on the Kingdom taking “concrete steps” to improve its rights record and democratic processes.

“We urge Cambodia to take meaningful steps to reopen political and civic space, including by resolving opposition leader Kem Sokha’s prolonged trial, and releasing other detained political and civil society activists, including U.S.-Cambodian citizen Seng Theary,” the Whitehouse said.

China is funding large-scale upgrades, including a deep-water port, at Ream Naval Base in Preah Sihanouk Province. Washington fears Beijing is building a military outpost.

“The President raised concerns regarding the situation at Ream Naval Base and underscored the importance of full transparency about activities by the P.R.C. military at Ream Naval Base,” the Whitehouse said, using the abbreviation for the People’s Republic of China.