Hillary Clinton has arrived in Laos, the first US secretary of state to visit the country in 57 years.

希拉里·克林顿抵达老挝，这是近57年以来首位出访老挝的美国国务卿。

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Mrs Clinton's landmark visit to Laos is part of a trip signalling growing US interest in Asia
She is expected to discuss plans to build a controversial Mekong River dam, which critics say would impact the environment and millions of lives.

The effects of Agent Orange, a defoliant used during the Vietnam war, are also likely to be on the agenda.

Mrs Clinton, who arrives in Vientiane from Vietnam, will then head to Cambodia for an Asean meeting.

The last top US diplomat² to visit Laos was John Foster Dulles in 1955.

The $3.8bn (£650m) hydro-electric dam project at Xayaburi has caused tension among Mekong region countries - Laos, Vietnam, Cambodia and Thailand.

In April, a multi-billion dollar contract was signed for a Thai company, CH Karnchang, to build the dam.

The Lao government has pledged not to go ahead with the project until environmental issues have been resolved.

However, activists³ say work on the project has already begun, with reports and photographs emerging of construction vehicles in the area.

'Pivot⁴ toward Asia'

Mrs Clinton's trip is part of a tour of Asia which analysts⁵ say signals the United States' growing interest in the region.

"My trip reflects a strategic priority of American foreign policy today," she told reporters in Mongolia earlier this week.

"After 10 years in which we focused a great deal of attention on the conflicts in Afghanistan and Iraq, the United States is making substantially increased investments - diplomatic, economic, strategic and otherwise - in this part of the world. It's what we call our pivot（中心点） toward Asia."