The poll showed that 36% of Americans approve of Biden's performance in office, down 2% from April, a release on the poll said.
The poll saw Biden lagging behind his presumptive political challenger in the November election, Donald Trump, particularly in US states believed to be crucial in determining the election winner, the release said.
The issue most contributing to the decline of Biden’s approval rating is the struggling US economy (for 23% of respondents), the release said. Forty percent of respondents said Trump had better policies for the economy.
Another important issue influencing Biden’s approval rating decline is the record level of illegal immigration (for 13% of respondents), the release said.
On the whole, Trump was viewed by respondents as having a better approach to foreign conflicts and terrorism, with 36% to Biden's 29%, the release added.