WASHINGTON, Sept 16 (Reuters) - U.S. President Joe Biden said on Thursday that there was evidence that gasoline prices should be falling and his administration was investigating why that was not the case.

"There's lots of evidence that gas prices should be going down but they haven't," he said, adding his team was "taking a close look at that."

In August, Biden's administration pressed OPEC and its allies https://www.reuters.com/world/middle-east/us-call-opec-its-allies-increase-oil-production-cnbc-2021-08-11 to boost oil output to tackle rising gasoline prices.

(Reporting by Nandita Bose and Jeff Mason; Editing by Lisa Shumaker)