SEOUL, Dec 30 (Reuters) - South Korea said on Friday it will impose mandatory COVID-19 tests on travellers from China, joining the United States, Japan and other countries in taking new border measures after Beijing's decision to lift stringent zero-COVID policies.South Korea would also restrict issuing short-term visas for Chinese nationals until the end of next month and temporarily halt increasing flights from China while using Incheon International Airport as the only gateway for any flights from the neighbouring country, Prime Minister Han Duck-soo said.Effective Jan. 5, travellers from China would be required to submit a negative result from a PCR test no more than 48 hours or a rapid antigen test taken within 24 hours before departure, and undergo another PCR test upon arrival starting Jan. 2, officials said.South Korean authorities said the new restrictions were needed after Beijing stopped publishing daily data on cases, raising concerns over a new wave of infections and mutations.While most of the new rules are set to be in place until the end of February, the Korea Disease Control and Prevention Agency said they could be extended."