That came with a call from Xi for stability along their shared border after fighting in March in Burma pushed thousands of people into China.
The spillover led to Beijing calling for a ceasefire between militias and Burmese security forces and Chinese troops drilling on the border.
Xi met Suu Kyi, who is Burma's foreign minister and de facto head of government, after the Belt and Road Forum. She is barred from the presidency under Burma's military-drafted constitution but leads the country in a specially created post of state counsellor.
While there was no word on what assistance China will provide on their border, Beijing last month offered to mediate in a row over the flight of around 69,000 minority Rohingya Muslims to Bangladesh to escape violence in Buddhist-majority Burma.