It is expected: foreigners continued to increase their positions in U.S. treasuries. Foreign holdings of U.S. debt hit $5.46 trillion from $5.292 trillion the previous quarter (Chart 1). That's an increase of 3%.
$16.28 trillion in debt is now partly in the hands of foreigners. The percentage = 5.46/16.28 = 33.5% (Chart 2).
As long as foreigners are willing to hold U.S. debt, there is no problem at all...
One word of caution though, the interest on this debt will be sucked out of the U.S. economy and flow to the foreigners.
China increased their U.S. treasury holdings to $1.156 trillion in September 2012 (Chart 3).