BEIJING — China is building a second aircraft carrier, the country’s Ministry of National Defense confirmed on Thursday. But unlike the first, this one will be produced entirely using China’s own designs and technology, the ministry said.

A spokesman for the ministry, Col. Yang Yujun, said at a monthly news briefing in Beijing that the second aircraft carrier was being built in Dalian, a port city in northeast China. He did not indicate when the ship would be completed.

China’s first aircraft carrier, the Liaoning, went into service in September 2012. It was built from a castoff, uncompleted vessel bought from Ukraine in 1998 and refurbished by the Chinese Navy.

“After taking into account a range of factors, the relevant authorities launched work on developing a second aircraft carrier, and we are now undertaking our own indigenous design and construction,” Colonel Yang said, according to a transcript of the news briefing on the ministry’s website.