The manufacturers of 10 high-cost drugs selected for the U.S. Medicare program's first-ever pricing negotiations have submitted counter offers to the U.S. government's initial proposal, U.S. President Joe Biden said on Monday.

The negotiation program, passed as part of 2022's Inflation Reduction Act, allows Medicare to negotiate prices for the high-cost drugs. Medicare covers Americans aged 65 and above.

The agency in August picked the first drugs for such negotiations, then the Biden administration sent its initial offers to manufacturers of the medicines, which include Bristol Myers Squibb and Pfizer's blood thinner Eliquis, in February.

A federal judge in Delaware on Friday upheld the law that requires drugmakers to negotiate prices, rejecting a challenge by AstraZeneca.