New Delhi, May 17 -- Moody's Ratings has downgraded the Government of United States of America's (US) long-term issuer and senior unsecured ratings to Aa1 from Aaa.

The downgrade, which marks a one-notch fall on Moody's 21-point rating scale, comes amid concerns over rising federal debt and interest payments, which have increased significantly over the past decade.

The rating agency said the move reflects the continued failure of successive US administrations and Congress to agree on measures that could reverse the trend of large and persistent fiscal deficits.

Moody's said "Successive US administrations and Congress have failed to agree on measures to reverse the trend of large annual fiscal deficits and growing interest costs. We do ...