China’s opening up is self-initiated and will not be forced by pressure from other countries, the country’s commerce ministry said on Sunday on its official Wechat account.

Zhong Shan, the head of the ministry of commerce, made the comments during a meeting with former U.S. Treasury Secretary Henry Paulson, adding that cooperation between China and the United States was the only right choice.

Trade tension between the two has flared since last week after President Donald Trump unveiled plans on Thursday to slap tariffs on potentially up to $60 billion in Chinese goods.