LONDON — Hu Jintao, given a head-of-state welcome in Washington, tried to show a friendly face toward America. He brought gifts in the form of contracts to buy American products, although most of these contracts had been closed earlier and some at least involve the purchase of American technology that the Chinese will doubtless replicate.

While admitting that there were differences of opinion on human rights he made no substantive concessions. He made no definite commitment about allowing the Chinese currency to appreciate, but seemed to accept that domestic demand in China should be allowed to expand.

Li Keqiang, the Chinese vice premier, who may be destined for the top slot in Beijing, has been on a European tour bringing gifts and contracts. In Edinburgh he presented the zoo with two pandas in a new piece of panda diplomacy. He announced that China intended to buy European bonds and Chinese companies would buy shares in European petrochemical companies. He made it clear that China supports European integration and wants the euro currency to flourish. To Spain he held out the prospect of China buying such consumer items as wine and olive oil.