Cambodia is expected to attract 7 million foreign tourists by 2020, with an estimated annual revenues of 5 billion U.S. dollars that year, Prime Minister Hun Sen said Thursday. "To achieve this ambitious goal, it is necessary to strengthen law implementation to safeguard tourists, and tourism quality and services should be improved," he told the Conference on Tourism Development Strategic Plan 2012-2020. The premier said that the government has been focusing on the development and improvement of physical infrastructures such as roads, seaports and airports in order to facilitate travelers. He disclosed that Cambodia has planned to build two new international airports -- one in Phnom Penh and the other in Siem Reap province. Each is capable to receive 10 million passengers a year. He did not unveil specific locations or time frames for the construction. Meanwhile, Hun Sen advised tourism officials to target Chinese, Japanese, South Korean and Indian tourists to push the country's tourism growth. Tourism Minister Thong Khon said at the conference that Cambodia is the destination of cultural and eco-tourism. "Tourism is the country's green gold," he said, adding that last year, the sector attracted 2.88 million foreign visitors, earning 1.9 billion U.S. dollars.