BEIJING (AFP) - The United States and China glossed over differences on human rights as they pledged here Saturday to work more closely in tackling the global economic crisis and climate change. Secretary of State Hillary Clinton and Chinese Foreign Minister Yang Jiechi focused on economic and environmental issues, while Chinese activists said police had sought to muzzle them during Clinton's high-profile visit. Giving hope for new cooperation between the world powers, Clinton and Yang told a press conference they had already begun planning for the Group of 20 summit in London on April 2. The pair was to meet again next month in the United States to coordinate positions for the summit where Presidents Barack Obama and Hu Jintao were to hold their first meeting since Obama took office in January. "We believe that by working together we will be able to tide over this financial crisis," Yang said. Reforming global financial regulations and international economic institutions will be among the top agenda items at the summit. One of export-driven China's chief concerns is that the United States, the world's biggest economy, will put up trade barriers, as evidenced by a "Buy American" clause in the huge US stimulus package approved last week. But Yang said after their meeting that he and Clinton had agreed to "reject trade and investment protectionism". For the US side, Clinton indicated Yang had given her an assurance that China would continue to buy US Treasury bonds, which is seen as vital for the United States to help pay for its 787-billion-dollar stimulus package. "I greatly appreciate China's continued confidence in United States Treasuries," Clinton told a joint press conference with Yang. Yang was more circumspect, but signalled China would not deviate drastically from its US Treasury policies. "We will make further determinations about the ways and the means we will use our foreign exchange reserves," he said. "(But) I want to emphasise here that facts speak louder than words." Clinton said the two countries " the world's biggest greenhouse gas emitters " agreed they had a "shared interest" in producing a successful deal at the Copenhagen summit in December aimed at combatting climate change. "The United States and China will build an important partnership to develop and deploy clean energy technologies designed to speed our transformation to low-carbon economies," Clinton said. Accompanied by her climate change envoy Todd Stern, she visited a General Electric power plant in Beijing that runs on natural gas, to highlight potential cooperation on clean energy. "This plant could be a model," Clinton said as she urged the Chinese to pursue economic growth based on clean energy and avoid the mistakes the United States and Europe made during their industrialisation last century. On Friday, Clinton angered Amnesty International and others critical of communist China's attitude towards human rights when she said she would not allow the issue to block progress on the most pressing global problems. The Chinese Human Rights Defenders group also said Saturday that a number of dissidents had been put under residential surveillance, questioned and followed by Beijing police in an effort to silence them during Clinton's visit. Both Clinton and Yang said they had discussed human rights issues, but stuck to general comments. Clinton said it was an "essential aspect" of US foreign policy, while Yang said it was "natural" for such different countries not to see eye to eye on human rights. Clinton met Hu shortly after meeting Premier Wen Jiabao. In their meeting, Wen remarked that "the global financial crisis is having a big impact on the entire world", and praised Clinton's call for international cooperation. On Sunday, Clinton will attend a church service and meet civil society leaders before flying home. Clinton began her Asian trip, her first overseas trip as secretary of state, in Japan on Monday, and then visited Indonesia and South Korea.