(CNN) -- On her second full day of a week-long goodwill tour in China, Michelle Obama lauded study abroad as a key part of U.S. foreign policy and encouraged students from all walks of life to consider joining the growing corps of citizen diplomats such study fosters.
"I'm here today because I know that our future depends on connections like these among young people like you across the globe," the first lady told an audience composed of Chinese and international students at Peking University.
"We believe that relationships between nations aren't just about relationships between governments or leaders -- they're about relationships between people, particularly young people."
Immersion in another country's culture does more than help a student's job prospects, she said. "It's also about shaping the future of your countries and of the world we all share. Because, when it comes to the defining challenges of our time --- whether it's climate change or economic opportunity or the spread of nuclear weapons -- these are shared challenges. And no one country can confront them alone. The only way forward is together."
She noted that China is the fifth most popular destination for Americans studying abroad, and that the Chinese represent the highest number of exchange students in the United States.
Obama, who grew up in a working-class family, said that as a student she never considered studying abroad and noted that many young people struggling to pay for school today may also feel that way. "That's not acceptable, because study abroad shouldn't just be for students from certain backgrounds," she said.
She quoted Philmon Haile, a University of Washington student who moved with his family from Eritrea to the United States as refugees when he was a child and then studied in China. "He said, 'Study abroad is a powerful vehicle for people-to-people exchange as we move into a new era of citizen diplomacy.'"
The technology revolution has changed the game, she noted. "You don't need to get on a plane to be a citizen diplomat," she said. "If you have an Internet connection in your home, school or library, within seconds you can be transported anywhere in the world and meet people on every continent."
She added that the battle of ideas that can result from such interaction "can be a messy and frustrating process," but said it was a critical one. "Because time and again, we have seen that countries are stronger and more prosperous when the voices of and opinions of all their citizens can be heard."
Obama's remarks came a day after she -- accompanied by her daughters and her mother -- visited a Beijing high school accompanied by China's first lady, Peng Liyuan.
She met with students at the public school as well as with 33 American students from a U.S.-based School Year Abroad program, which costs $50,000 per year and occupies the sixth floor of one of the school's buildings.
More than half of the 250 students at its schools in China, France, Spain and Italy receive "some sort of need-based aid," said SYA President Jack Creeden, in a telephone interview. "The average award is $26,000."
Obama's schedule does not include a news conference, and she is not expected to answer questions from professional reporters during the trip. But on Saturday, she answered several of the more than 300 questions filed by CNN iReporters about studying abroad and international travel. They will be posted Tuesday.
Also on Tuesday, she will answer questions submitted by U.S. classrooms as part of a webinar series by Discovery Education and the White House.
U.S. President Barack Obama is expected to meet with Chinese President Xi Jinping at next week's Nuclear Security Summit at The Hague, Netherlands.