By David Brunnstrom VIENTIANE (Reuters) - Laos wants to see maritime rights respected and avoid a military build-up in the South China Sea, U.S. Secretary of State John Kerry said on Monday, after a meeting with Laos' Prime Minister Thongsing Thammavong to urge ASEAN unity in the face of Chinese claims. Laos is the 2016 chair of the 10-nation Association of Southeast Asian Nations (ASEAN) and hosts a summit later in the year that will include the leaders of the United States and China. "He was very clear he wants a unified ASEAN and he wants maritime rights protected, and he wants to avoid militarization and to avoid conflict," Kerry told reporters after meeting Thongsing in Vientiane, the capital of Laos.