TOKYO/ LOS ANGELES - Tokyo and Washington plan to install a US early-warning radar system at a coastal base near Kyoto to bolster defences against the North Korean missile threat, reports said Sunday.The X-band radar, capable of precisely tracking the trajectory of a ballistic missile, allows US forces to launch intercept missiles from the ground and sea once a ballistic missile has been detected. It will be the second X-band radar system to be installed in Japan after another was set up in northern Aomori prefecture.The X-band radar system will be built in an Air Self-Defence Force base in Kyotango, northwest of Kyoto, on the coast of the Sea of Japan, or East Sea, Kyodo News and Jiji Press agencies reported, citing unnamed sources.The location was picked as it was likely that a North Korean missile targeting Guam or Hawaii would fly over western or central parts of Japan, Kyodo said. Japanese Prime Minister Shinzo Abe and US President Barack Obama confirmed in their meeting Friday in Washington that the two countries would work together on the radar installation, the reports said.Separately, the Los Angeles Times reported that US officials made two secret visits to North Korea last year in an effort to improve relations after North Korea leader Kim Jong Un assumed power.Citing unnamed former US officials familiar with the trips, the newspaper said the visits in April and August were aimed at encouraging the new leadership in Pyongyang to moderate its foreign policy. The April trip was led by Joseph DeTrani, who at the time headed the National Counterproliferation Center in the Office of the Director of National Intelligence, the report said. It was unclear who led the August trip, the paper noted.The Times quotes the officials as saying that Sydney Seiler, a veteran CIA analyst, who speaks fluent Korean and is in charge of Korea policy at the National Security Council, went on both trips. DeTrani left the government last year and now heads the Intelligence and National Security Alliance, an industry group, the newspaper noted.