In the following years Thai influence grew until challenged by Western powers. In 1795 the Thai seized the provinces of Battambang and Siem Reap in Cambodia, where throughout the first half of the next century Chakkri kings would resist Vietnamese incursions. The conflict between the Thai and the Vietnamese was resolved finally by a compromise providing for the establishment of a joint protectorate over Cambodia. The Thai also pressed their claim to suzerainty in the Malay state of Kedah in the face of growing British interest in the peninsula. As a result of the Anglo-Burmese War (1824-26), Britain annexed territory in the region that had been contested by the Thai and the Burmese for centuries. This move led to the signing of the Burney Treaty in 1826, an Anglo-Thai agreement that allowed British merchants modest trade concessions in the kingdom. In 1833 the Thai reached a similar understanding with the United States.