China has taken measures to tighten exit and entry across land borders to contain the risk of imported novel coronavirus cases, a senior official with the National Immigration Administration on Monday.

Liu Haitao, director of the National Immigration Administration's border inspection department, told a daily briefing in Beijing that all land border ports have banned exit and entry by people from a third country.

Authorities have suspended the issuance of exit and entry certificates in border areas applied for non-essential reasons, as well as passenger transport through land ports, Liu said.

Authorities also have advised against people trying to enter or exit for non-essential reasons, such as tourism and visiting friends, he said.

China, with a land border of 22,000 km, has 91 land ports in addition to a large number of border passages for inhabitants in the border areas, so there is a high risk of importing cases via land passages, said Liu.

Thanks to the tightened measures, the number of people from abroad, including those who live in the border areas, exiting or entering China has dropped from over 60,000 per day before the outbreak to about 10,000 per day now, he said.

He added that border ports that have been closed will remain closed, and the opening of the seasonal ports will be delayed. The administration and local authorities will strengthen the supervision of the closed border ports.

The administration will support and cooperate with local governments in implementing the measures of centralized quarantine for entry personnel, and prevent Chinese citizens who are within their 14-day quarantine period from leaving the country.

It would also work with Customs' quarantine departments to strengthen the inspection of entry personnel and transport vehicles, and prevent the entry of foreigners with abnormal body temperature, Liu said.

It would crack down hard on illegal immigration and promptly repatriate detained illegal immigrants in accordance with the law to ensure security and stability of the border areas, he added.

Mi Feng, a spokesperson for the National Health Commission, said at the daily briefing that the risk of imported cases from the countries bordering China continues to rise.

Border provincial areas, including Southwest China's Yunnan, South China's Guangxi and Northeast China's Heilongjiang, have reported multiple imported cases recently.

Earlier in March, border authorities in Guangxi Zhuang autonomous region found and repatriated 13 foreign nationals who climbed mountains and illegally crossed the border into Bainan township of Baise city.

A border management detachment team in Xishuangbanna Dai autonomous prefecture in Yunnan province on March 29 cracked a case in which 56 people were smuggled across the border; all were arrested.