Cambodia's first prime minister, Ung Huot, has arrived in Vietnam for talks which will focus on disputed oil and gas exploration areas in the Gulf of Thailand.

Ung Huot will meet his Vietnamese counterpart, Phan Van Khai, and other senior figures.

The BBC correspondent in Phnom Penh says Cambodian officials describe the trip as a friendship visit.

However, she says that apart from discord over off-shore exploration, other issues including border disputes and discrimination against Vietnamese living in Cambodia are expected to be addressed.