Chinese holdings of Treasury securities fell $5.4 billion, or less than half a percent, to $1.15 trillion in January from December.

January's level was $20.6 billion lower than the peak of $1.175 trillion in October.

China's holdings are keenly watched as a sharp turn away from US bonds by their biggest foreign buyer could send US debt costs skyrocketing.

Moreover, leaked diplomatic cables in February vividly showed China's willingness to translate its massive holdings of US debt into political influence on issues ranging from Taiwan's sovereignty to Washington's financial policy.

Japan was a distant second among foreign holders of US debt, with $886 billion, the Treasury figures showed.

Overall foreigners made net purchases of US long term debt in January to the tune of $51.5 billion, lower than the $55 billion expected by analysts.