Despite a grueling schedule that involved traveling to four countries in just seven days, Hillary Clinton looked as sprightly as ever when she addressed Chinese students in Beijing at the weekend.

Dressed in a smart black suit, the United States secretary of state raised her index finger and said: "I'm pleased I have a chance to see some of the young people who are going to make a difference in the future."

US Secretray of State Hillary Clinton speaks during her visit to the Beijing Taiyanggong Gas-fueled Thermal Power Co., Ltd. (Taiyanggong Power Plant) of the Beijing Energy Investment Co., Ltd. in Beijing, capital of China, Feb. 21, 2009. [Xing Guangli/Xinhua]

But the 10-minute speech at China's biggest thermo-energy plant on Saturday was not Clinton's first chance to meet the public on her week-long maiden overseas trip.

Apart from singing on a television show in Indonesia, she also chatted with Japanese students during a visit to Tokyo University last Tuesday, with topics ranging from her conversation with the Japanese empress to baseball and robots.

"This is what diplomacy is about," Clinton said. "It doesn't just operate government to government. It operates people to people."