Concerns over slowing growth and trade tensions underscore the urgent need for a "swift policy response," such as monetary easing, across Asia, HSBC said in a Friday note.

Monetary policy is the "first line of defense" to counteract recent market and economic volatility, as opposed to fiscal measures which could be slower to implement under dampened confidence, the equity research firm said.

Controlled inflation and higher real interest rates support "more forceful action," HSBC said, adding that central banks do not need to wait for the US Federal Reserve to carry out rate cuts.

Greater deflationary pressures, a weaker US dollar and lower commodity prices should also enable regional central banks to prioritize growth over exchange rate dynamics, the equity research firm said.