Apple CEO Tim Cook has once again defended his company against allegations of poor working conditions for its Chinese employees.

Speaking in a keynote address at the Goldman Sachs Technology and Internet Conference, where he normally speaks about sales figures and market share, Cook was asked about working conditions in Apple's supply chain.

Cook said: "The first thing I would want everyone to know Apple takes working conditions very, very seriously...we care about every worker. I spent a lot of time in factories personally [and] we understand working conditions at a very granular level.

"I realise that the supply chain is complex, but my commitment is very, very simple. We believe that every worker has the right to a fair and safe work environment, free of discrimination, where they can earn competitive wages, and voice their concerns freely. We believe that education is the great equaliser."

Apple has come under heavy criticism for the treatment of staff at Foxconn's Chinese production plant, which is responsible for manufacturing iPhone and iPads. A recent New York Times article claims that workers at Foxconn are treated badly, earn little money and work in a dangerous environment.

Cook also said: "You can read the details on problems we're looking to fix on our website, but I can tell you that no one in our industry is doing more to improve working conditions than Apple. We are constantly auditing facilities going deep into the supply chain, looking for problems, finding problems and fixing problems."

The speech comes soon after Apple enlisted the Fair Labor Association to begin an audit of its final assembly vendors. "Their audit is probably the biggest audit in manufacturing history," the CEO added.

With regard to underage workers, Cook admitted that "it's extremely rare in our supply chain," but added that the hiring of underage staff is a sackable offence.

The New York Times report claims that safety at Apple's supply chains is poor and has led to several high-profile incidents; explosions in the past have killed employees, but Cook aimed to reassure the industry, saying: "We don't let anyone cut corners on safety.

"If there is a problem on safety, we seek out the foremost experts and set a new standard and apply that to the entire supply chain. We focus on the details."

Apple blog MacRumors has posted the entire transcript of the keynote, where Cook also spoke about iPhone and iPad sales, and opportunities Apple has in emerging markets.