From the Financial Times:
China will continue to buy US Treasury bonds even though it knows the dollar will depreciate because such investments remain its “only option” in a perilous world, a senior Chinese banking regulator said on Wednesday.
China has used the dollars it accumulates selling manufactured goods to US consumers to accumulate the world’s largest holding of Treasuries.
Despite that the Chinese feel trapped into buying more treasuries, they aren't happy about it. They used very strong and stern language to describe their disgust: "We know the dollar is going to depreciate, so we hate you guys but there is nothing much we can do.”