Chinese Premier Wen Jiabao has signed $15 billion worth of trade agreements with Germany as his delegation agreed to purchase 88 European-made Airbus planes.

The contracts came at the end of the Chinese leader's three-country tour of Europe, marked by billion-dollar deals with Britain and Hungary and promises of more to come.

Mr. Wen also said his country could buy up some of Europe's debt, easing the financial pressures squeezing the eurozone from economically-weakened countries like Greece, Spain, Ireland and Portugal.

German Chancellor Angela Merkel welcomed the deals and said she hoped that trade between the two nations would rise to an annual volume worth $280 billion by 2015.

But while Ms. Merkel welcomed the economic boost, she also called for China to act in a “transparent” manner toward its recently-released dissidents, artist Ai Weiwei and activist Hu Jia.

Mr. Wen pushed back, saying that just as China respected Europe's political model, it expected the European Union to respect for Chinese sovereignty.

Chancellor Merkel had said before Mr. Wen's arrival that she would not soft-pedal human rights issues despite Germany's desire for increased economic cooperation with China.

In Britain, despite differences on human rights issues, the Chinese premier and British Prime Minister David Cameron signed trade deals worth $2.2 billion.

Airbus said Tuesday that China had agreed to buy 88 of its A320 planes. The company said in a statement Tuesday that by the end of May 2011, there were some 575 A320 aircraft in operation with 13 Chinese airlines.

At their Monday summit, the British and Chinese leaders expressed optimism about increasing bilateral trade with a goal of $100 billion by 2015. But they also voiced differences over human rights and Libya.

Mr. Wen called for a negotiated settlement to the Libyan crisis. Referring to the NATO air campaign against pro-Gadhafi forces, he said, “Foreign troops may be able to win war but they can hardly win peace.”

Mr. Cameron told reporters he raised the issue of human rights during his talks with the Chinese premier. But he added, there is no 'trade-off” between trade and human rights.

Earlier, the Chinese premier also offered to buy some Hungarian debt while signing a number of agreements with Budapest to boost trade between the two nations.