NEW DELHI — Chinese President Xi Jinping heads to India for a summit on Saturday that could mark the biggest step in a cautious thaw after years of hostility between the two countries. Xi's visit for the September 12-13 BRICS summit would be his first trip to India since October 2019, and follows Prime Minister Narendra Modi's August 2025 visit to China. The nuclear-armed Asian giants have been been slowly improving ties since a deadly 2020 border clash. Flights, some visas and high-level contacts have gradually resumed. But deep mistrust remains, with their disputed Himalayan frontier, a heavy trade deficit and strategic rivalry complicating ties. Here are five things to know: Border comes first The relationship was transformed by the June 2020 Himalayan border clash, when fighting in Ladakh killed 20 Indian and four Chinese soldiers. In October 2024, Beijing and Delhi agreed on patrolling arrangements, paving the way for renewed political contacts. But the underlying territorial dispute remains unresolved, and both sides retain heavy military deployments along their roughly 3,500-kilomet