Cambodia attracted about 2.3 million foreign visitors in the first six months of 2015, an increase of 5.6 percent compared with the same period last year, Tourism Minister Thong Khon said Tuesday.

"Vietnam, China and South Korea are still the largest sources of foreign tourists to Cambodia,"he said, noting that the slow growth was due to the outbreak of the Middle East Respiratory Syndrome (MERS) in South Korea in May, which is also a main gateway of international tourists to Cambodia.

The minister predicted that Cambodia is expected to greet approximately 5 million foreign tourists in 2015.

Tourism is one of the four pillars supporting the economy. The Southeast Asian nation attracted 4.5 million foreign visitors last year, generating the gross revenue of more than 3 billion U.S. dollars.

The country is famous for two cultural sites in UNESCO's World Heritage List. One is the 12th century Angkor Wat Temple and the other is the 11th century Preah Vihear Temple. Besides, it has a 450-km pristine coastline, which is one of the World's Most Beautiful Bays.