Treasurer Josh Frydenberg has vowed the government will take "the necessary actions" to protect the Australian economy amid fresh signs of a global slowdown and fears the United States could be on the cusp of a recession.

In an intervention designed to calm nerves after $60 billion was wiped from the value of Australia's top-200 listed companies in a day, Mr Frydenberg said the nation was well placed to absorb any impending global shock but he was "certainly not complacent".

Markets now put the chance of an American recession within the next 12 months at 1-in-3 after a key economic indicator, the bond yield curve, "inverted" for the first time since 2007. The curve has inverted - when the interest rates on short-term bonds are higher than those on long-term bonds - ahead of every American recession in the past 50 years.

While Mr Frydenberg and the Coalition are committed to delivering a promised budget surplus, the Treasurer's pledge to take "necessary actions" suggests the government has flexibility to react to a major global downturn and would be prepared to develop a new policy response if needed.