Clinton arrived in Vientiane for a three-hour official stopover enroute to Phnom Penh, where she is to attend several regional conferences.
She was scheduled to first meet with Lao Foreign Minister Thongloun Sisoulith and then Prime Minister Thongsing Thammavong, Lao Foreign Affairs Ministry officials said.
"The meeting with Thongsing promises to be pretty brief," said a Lao official who requested anonymity.
After the talks, she would visit the National Handicap Rehabilitation Center and the Phra Keo, or Emerald Bhudda, temple before departing for the Cambodian capital.
"This groundbreaking visit to Laos marks the first by a secretary of state in 57 years," the US State Department said.
Lao-US relations have been strained over the past decades by the legacy of the US military involvement in Vietnam in the 1960s and'70s, which saw Laos and Cambodia dragged into the conflict.//DPA