Follow @SCMP_News Chinese students and parents are demanding an apology from US Vice-President Joe Biden for "insensitive" comments, weeks after he referred to China as the nation that cannot “think different” or “breathe free” during a commencement speech at the University of Pennsylvania. “I believe Biden should apologise over his inappropriate comments made at my commencement in the face of at least hundreds of Chinese people,” Zhang Tianpu, a graduating Wharton senior and Chinese citizen, told the South China Morning Post on Wednesday. “It was a humiliating experience,” he said. “And how can a graduation speech be this political?” Zhang and his peers have already drafted a letter to Biden demanding an official apology . The letter has 343 signatures as of Wednesday and will be sent to the university’s president before reaching Biden's desk. Requests for comment from Biden's office have not been returned. Biden’s comments, which were called "inappropriate", hugely disappointed the Chinese in his audience. They were delivered in the middle of his May 13 speech, reported by the Guardian as “ by far the funniest of the recent commencement addresses” . But not everyone appreciated his jokes. Touching on the concern that “the Chinese are going to eat our lunch”, Biden assured his audience that they had nothing to fear. “Their problems are immense, and they lack much of what we have,” he said, citing America’s universities, its “open and fair legal” system, vibrant venture capital markets and innovative minds. The key to all these, Biden argued, was the ability to “think different”, in a reference to Steve Jobs' slogan for Apple. “You cannot think different in a nation where you cannot breathe free; you cannot think different in a nation where you aren’t able to challenge orthodoxy, because change only comes from challenging orthodoxy.” To which Zhang argued: “Come on, my ancestors were challenging orthodoxy even before his ancestors got to America.” Biden mentioned China a second time towards the end when he spoke of his 10-day visit to the Middle Kingdom. Of then president-to-be Xi Jinping, he said: “He’s a strong, bright man, but he has the look of a man who is about to take on a job he’s not at all sure is going to end well. I mean that seriously." In a post that went viral on China’s social media, Zhang interpreted Biden’s message in the following words: “So because China is ---- up, we are well-positioned. We are well-positioned to lead the world into the 21st century, ” he wrote. ”This is what I think he was saying.” In an e-mail sent to The Post , Zhang dismissed criticism that he was overreacting. “After four years of sweat and toil, after four years of spending Chinese New Year without your family, and after four years of eating tasteless food, you have finally earned this day when you can proudly graduate. But you know that all is worth it because you want to learn from an advanced developed country, something you can use to contribute to your hometown. So you decide to call up all of your friends and family to fly across the Pacific Ocean to celebrate with you on this special day. Then, on your graduation day, you get up super early, happily dress up in your academic regalia, and have your friends and relatives seated in the field, cameras ready, recorders turned on, all excited.” “And then all of sudden, the graduation speaker, who is supposed to be there to congratulate you on your achievement, says to you: you and your nation suck. Regardless of whether that statement is true, how would you feel?” Zhang had first ranted on China’s popular social media website Renren. His post has since drawn thousands of comments, from supporters and critics. “Biden isn’t obligated to please China,” commented a reader. “And the right reaction is to catch up with America, instead of whining about it.” “Don’t attribute to political agenda what can easily be explained by stupidity,” another wrote.