Seoul, Jan 15 : The top nuclear envoys of South Korea, the US and Japan have condemned North Korea's latest ballistic missile launch during their phone talks earlier this week, Seoul's Foreign Ministry said on Monday. North Korea test-fired an intermediate-range ballistic missile into the East Sea on Sunday in its first ballistic missile launch this year, according to South Korea's Joint Chiefs of Staff. It came after North Korea fired hundreds of artillery shells near the inter-Korean maritime border in the Yellow Sea from January 5 to 7, Yonhap news agency reported. Kim Gunn, South Korea's special representative for Korean Peninsula peace and security affairs, spoke by phone on Sunday to discuss the latest provocation with his US and Japanese counterparts, Jung Pak and Hiroyuki Namazu, respectively, the ministry said. The envoys denounced the launch as a violation of the UN Security Council resolutions that threatens the peace and stability of the Korean Peninsula and the region. Pointing out the North's illicit provocations as the "root causes" of instability in the region, the three sides emphasized their trilateral cooperation will be bolstered even further as North Korea escalates its provocations. They also agreed to keep close tabs on North Korean Foreign Minister Choe Son-hui's visit to Russia this week amid deepening military cooperation between the two countries. /IANS