BEIJING -- China's Ministry of Commerce announced on Wednesday that it would ensure the supply of pork to Hong Kong despite the recent decline in the number of pigs on the mainland.

A spokesman with the ministry said that during May the mainland had supplied Hong Kong with an average of 4,268 pigs per day and the supply could "generally" meet demand. He did not say how many pigs were supplied to Hong Kong in April.

"Rising feed and pork prices have increased the cost of pork supply," said the spokesman.

He said the ministry would encourage neighbouring Guangdong province to provide more pigs, intensify supervision and management of pork supply and work with the General Administration of Quality Supervision, Inspection and Quarantine to maintain the quality of registered pig farms.

The Ministry of Communications has issued an urgent notice calling transportation departments to give priority to the delivery of pork and live pigs.

The authorities will launch an emergency plan if necessary and the toll for vehicles carrying pork or live pigs will be reduced, said the notice.

According to the Ministry of Agriculture, in April live pigs nationwide were priced 71.3 percent higher than a month earlier, and pork 29.3 percent higher.

In Beijing, the pork price went up more than 30 percent in recent days, while wholesale prices in Shanghai hit 16 yuan (US$2.1) per kilogram, the highest in a decade, up 20 percent on the previous month.

The price hikes were caused by a marginal decline in the pig population this year as pig raisers made losses over the the past couple years and were reluctant to raise pigs, said Xu Lianzhong, a senior economist with the price supervision center under the National Development and Reform Commission.

The outbreak of blue ear disease, also known as Porcine Reproductive and Respiratory Syndrome (PRRS), which caused pig deaths and culling was an immediate cause of the short supply, said Xu.

The General Office of the State Council, China's cabinet, has urged local governments at all levels to ensure the continuity of pork supplies amid concerns over soaring pork prices.