SHANGHAI — China gave its economy a shot in the arm on Sunday amid signs of a slowdown, as it freed up more than $100 billion for banks to use to help small businesses and heavily indebted companies.

The money is intended to help Beijing dance a complicated two-step. China is trying to curb the country’s addiction to borrowing, which over the past decade has mired vast areas of the economy in debt. But that effort is showing signs of hurting growth. China is hoping it can help spur growth by steering loans where they are needed and blocking them where they are not.

Beijing’s balancing act could soon get more difficult. President Trump is ratcheting up his threats to impose more tariffs on Chinese-made goods. While China’s economy is more than big enough to absorb the blows, Beijing could be forced to reopen the lending spigots if the threats devolve into an all-out trade war.

China in essence told the country’s banks on Sunday that they do not have to sock away as much for a rainy day, allowing them to lend the money instead. The central bank said that, effective July 5, it would reduce by half a percentage point the share of overall deposits that commercial banks and other savings institutions are required to deposit at the central bank, a measure known as the reserve requirement ratio.