"This means seniors are going to pay less for their prescription drugs, while we're changing circumstances for people on Medicare by putting a cap, a cap of a maximum of $2000 a year for their prescription drug costs."

The bill is seen as the biggest climate package in U.S. history, and also allocates funds for veterans affected by toxic burn pits from oversea bases.

At a White House event, Biden was joined by Democratic leaders including Senator Joe Manchin of West Virginia, whose support was crucial to passage of the Inflation Reduction Act along party lines after he had initially opposed a similar measure.