Twitter co-founder Jack Dorsey said Thursday the micro-blogging website would "love" to have a presence in China, the world's largest online market, if only it was allowed to compete there. Chinese censors block overseas social networking sites such as Twitter and Facebook, while allowing homegrown micro-blogging services like Weibo, run by Sina Corp. "The important fact is that we are just not allowed to compete in this market," Dorsey, who is also Twitter chairman, told the All Things Digital AsiaD technology conference in Hong Kong. "Look at Weibo, what is happening, certainly the way that people are using it is amazing and we see more and more activities. "They can compete in our markets and we'd love to be in there, but right now that's just not possible." He added: "We would love to have a strong Twitter in China but we need to be able to do that." China has the world's largest online population of more than 500 million users. The number of Weibo users in China has more than tripled this year to hit 195 million at the end of June, the latest official data show. Many people still access Facebook and Twitter through virtual proxy networks that circumvent the "Great Firewall of China" that blocks sites or snuffs out Internet content on topics considered politically sensitive. Created in 2006, Twitter's text-based posts of up to 140 characters attract more than 400 million users every month, with an average of 230 million Tweets fired off daily. It has become a key tool for social activists trying to mobilise public opinion, such as during the recent Arab Spring uprisings in the Middle East, and Dorsey said he intended to keep it that way. "We want to build a service that people can communicate freely on," he said. "That's he most important thing for us to uphold and that's the most important thing for us to defend."