Australia will challenge China's tariff on its barley exports in an appeal to the World Trade Organization (WTO).

It marks the first defensive action from Australia in response to a number of China's sanctions on a range of goods this year.

Beijing has imposed blockages or levies to dairy, meat, wine and others as political tensions have worsened.

This has caused alarm in Australia as China is its biggest trading partner, accounting for close to 40% of exports.

Earlier this week, Chinese state-controlled media reported that Australian exports of thermal coal - the third biggest export to China - would face restrictions.

Beijing declined to confirm the reports. It has previously accused Australia of "unfriendly" and "hostile" attitudes towards it.

Tensions have grown over China's alleged foreign interference and influence in Australian affairs.

'Taking it to the umpire'

China's 80% tariff on barley - imposed in May - was the first Australian agricultural export to be sanctioned this year, and came after Chinese trade officials alleged illegal dumping practices.

The Australian government has denied this, and said its repeated requests to Beijing for dialogue on the trade blows have been ignored.