Google co-founder Sergey Brin has revealed that some of parent company Alphabet's various units may do business in China. The remarks indicate that Google could make a return to the country it left in 2010.

Brin, who is president of Alphabet, told the Wall Street Journal that the company's new organizational structure would allow each unit to operate in whatever market it wants. "Each Alphabet business can make its own decisions on which countries to operate in. We already do quite a lot of business in China, although it has not been an easy country for us."

Although it does sell ads to businesses in China, Google's services are not officially available in the country. The Wall Street Journal reported last month that Google was discussing the possibility of launching an Android app store in China.

Google left China in 2010 after it was hit with a massive cyberattack and due to increasing tensions over the Chinese government's strict censorship laws. At the time, Brin was highly critical of China's government.

Speaking on Wednesday at an invent for Project Loon, which is aimed at delivering internet services from high-altitude balloons, Brin said that China is among the countries which have expressed interest in using the technology to expand its internet coverage.

Despite Brin's words, China may not be ready to welcome Alphabet back into the country with open arms. During Xi Jinping's state visit to the US last month, the company was notably absent from the list of guests invited to meet the Chinese President - possibly a sign that the Asian country is still sore over Google's very public criticism of its government five years ago.