But he said: "China also encourages capable and credible Chinese companies to invest in New Zealand.
"We hope New Zealand will provide them with an enabling policy environment and facilitate Chinese investment so as to scale up two-way investment and achieve all-round and balanced growth in our business ties.''
Dr Norman said the visit and the opinion piece "places enormous pressure on the ministers currently involved in making the final decision on the Crafar farms deal.''
Land Information Minister Maurice Williamson and Associate Finance Minister Jonathan Coleman will make the decision after receiving more information from the Overseas Investment Office.
Mr Jia is the highest-ranking visitor from China since Vice-President Xi Jinping's visit in July 2010, notable for a scuffle between his security and Dr Norman over the display of a Tibetan flag.
Mr Jia's visit marks the 40th anniversary of diplomatic relations between New Zealand and China.
In 2009 the Spanish National Court indicted Mr Jia along with former President Jian Zemin, Luo Gan, Bo Xilai, and Lu Guanzheng with crimes of torture and genocide against Falun Gong.