It followed the first 20-minute phone call on Wednesday after North Korea launched long-range ballistic missile Hwansong-15, which was said to be able to reach the US mainland.
Yonhap News Agency quoted a source from the South Korean President’s Office that said both leaders agreed on tougher sanctions and pressure until North Korea abandons its nuclear and missile program and return to the negotiating table. The source said the two leaders didn’t mention a military solution and maritime blockage of North Korea has never been an option.

In related news, US Secretary of Defense James Mattis pledged to stick to diplomatic solutions after North Korea’s latest inter-continental ballistic missile test.   

South Korea's Air Force said on Friday it has created a bigger airborne intelligence, surveillance and reconnaissance unit in response to growing nuclear and missile threats from North Korea. The new unit is tasked with monitoring the North's related activities around the clock in close coordination with the US.

At Thursday’s meeting with the US Secretary of State Rex Tillerson, German Foreign Minister Sigmar Gabriel said his country will reduce the number of its embassy’s staff in Pyongyang and request North Korea’s Embassy in Berlin to do the same.