BEIJING (Reuters) - South Korean President Moon Jae-in will visit China from Dec. 13-16, China s official Xinhua news agency said on Wednesday, citing Foreign Ministry spokesman Lu Kang. Xinhua did not give further details but the visit will come at a time of heightened tensions on the Korean peninsula.  The two countries are seeking to mend ties frayed by a year-long spat over the deployment of a U.S. anti-missile system in South Korea. The anti-missile system was deployed amid growing concern over North Korea s nuclear and missile programs. 