Total foreign holdings of US long-term securities in March reached 4.4792 trillion US dollars, up from 4.4743 trillion dollars from the previous month, but China trimmed its holdings for the fifth straight month, the US Treasury Department said Monday.

China, the largest holder of US Treasury securities, reduced its holdings from 1.1541 trillion dollars in February to 1.1449 trillion dollars in March.

However, Japan, the second largest foreign holder of US government debt, raised its holdings from 890.3 billion dollars in February to 907.9 billion dollars in March.

Britain, the third largest holder also boosted its holdings to 325.2 billion dollars in March from 295.5 billion dollars in February.

The debt figures are closely watched at a time when more and more investors believe that the US soaring debt is unsustainable. The Treasury Department said Monday it has hit the 14.29 trillion dollars legal ceiling on borrowings.