The problem has been linked to the Ministry for Primary Industries' recent name change, but Mr Key said there had also been recent changes to procedures on the Chinese side.
"That's quite a good long term thing because they are working on making sure there's a more robustness about their system, therefore the issue of counterfeit meat, meat that is claimed to have come from New Zealand but maybe wasn't from New Zealand can be combated.
"In the long term it's probably a good thing for New Zealand but there has been a short term hiccup."
Following a briefing earlier today from officials, Primary Industries Minister Nathan Guy said he was more confident of progress.
"From time to time these kind of technical delays will occur. This is a temporary issue, but we're confident it can be resolved", Mr Guy said.
"This is my number one priority to get the meat moving off the wharf and into the consumers."
Mr Guy said shipments had initially continued without incident for several weeks after the MPI name change took effect on March 1 this year but problems had emerged early last week.
"Basically we need to get the paper work in order to satisfy the Chinese officials."
But MPI deputy director-general Andrew Coleman was unable to say exactly what the problem with the paperwork was.
"We are not being told at this stage what the specific issue is."
Mr Guy said the problem was not a food safety issue. He also said some shipments were getting through.
Mr Coleman said he was aware of reports that China's domestic pork and poultry industries may have had a hand in the block on New Zealand sheep and beef imports but had he no official reports to that effect.
Chinese officials had indicated they had an issue with technical documentation.
"We have officials with them today and we're exploring exactly what is the issue with that information.
"We're with them today right now talking through what is their exact concern because we will remedy that concern."
