China would facilitate his visit early in 2014 after the result of the Government inquiries were known.
Asked if the president had expressed any concerns, Mr Key said "the fact that he was engaged, understood and was briefed tells you that we can't take this situation lightly."
The message the government would be giving Fonterra was the same message it would be giving to its own regulator, the Ministry of Primary Industries - "and that this is serious stuff."
"We send about $8 billion worth of product to China every year; there are consequences if mistakes are made or if we don't reach the gold standard."
China suspended imports of Fonterra whey powder and dairy base powder in August after testing by Ag Research in New Zealand suggested 38 tonnes of whey concentrate could contain toxin-producing clostridium botulinum.
Companies which used the product also recalled products containing the concentrate, including dairy giant Danone which recalled its baby formula products in eight countries.
Further testing revealed that non-toxic producing bacteria had been present but the crisis damaged the reputation of New Zealand baby formula producers across the board.
Mr Key said he had put in ''a plug" to President Xi for small companies that were having their baby formula held up at ports.
"He can understand the plight of those companies and the issues involved and he was confident we could work our way through those."
The president said Chinese consumers were aware of what had taken place but they had historically respected New Zealand's products for very high safety standard and they were standards Chinese companies tried to emulate.
Mr Key invited President Xi for a visit - he has been before but not as President.
A visit could be possible at the end of next year when Australia is due to host the G20 summit.