Tokyo on Friday urged North Korea to continue its probe into Cold War abductions of Japanese nationals, after Pyongyang accused Japan of internationalizing the issue and hinted it would halt investigations.

The Japanese government protested that it was keeping its side of a bilateral bargain made last year, when the North agreed to re-investigate all instances in which Japanese citizens were snatched.

South Korea said Friday it will push for talks in the coming week with the North over their Kaesong joint industrial zone, after reports Pyongyang has taken fresh steps to unilaterally implement a wage hike.

The North announced last month that it would raise wages of the roughly 54,000 North Korean workers employed in the 125 South Korean firms operating in Kaesong.

North Korea has threatened "merciless punishment" against South Korea if it goes ahead with plans to open a U.N. field office in Seoul for monitoring the North's human rights record.

The Committee for Peaceful Reunification of Korea (CPRK), a state body handling inter-Korean affairs, said late Monday that the office was an "unforgivable provocation" and would become a "first-strike target."

Thousands of U.S. and South Korean troops, backed by helicopters and jet fighters, staged a massive, amphibious landing drill Monday -- the centerpiece of an annual military exercise condemned by North Korea.

A total of 7,600 soldiers, including 3,500 marines, along with 80 aircraft, 30 ships, and scores of armored vehicles and tanks, took part in the drill to secure a bridgehead along the coast of Pohang, some 360 kilometers (223 miles) south of Seoul.

The U.N. Human Rights Council on Friday harshly criticized North Korea for the "systematic abduction" of foreigners, after a U.N. investigation found the country had snatched up to 200,000 foreign nationals.

But the 47-member rights body's resolution was slammed by North Korean ambassador Ri Hung Sik, who claimed it was a "political plot filled with frauds and distortions".

North Korea weighed in Thursday on the proposed deployment of a U.S. missile defense system in South Korea, criticizing it as a Cold War-era move to "contain" China and Russia.

The North Korean response appeared aimed at exploiting tensions between Washington, Beijing, Moscow and Seoul over the Terminal High-Altitude Area Defense (THAAD) system.

Japan on Thursday successfully launched a replacement spy satellite, its aerospace agency said, as an existing device comes to the end of its working life.

Tokyo put spy satellites into operation in the 2000s after its erratic neighbour North Korea fired a mid-range ballistic missile over the Japanese mainland and into the western Pacific in 1998.

Russia on Tuesday warned the United States against sending a ballistic missile defence system to South Korea, saying it could threaten regional security.   

Washington says it wants to deploy the system, known as THAAD, to South Korea as a deterrent to military provocation by North Korea.

North Korea on Tuesday ruled out any apology over the 2010 sinking of the South Korean navel corvette Cheonan, and demanded Seoul lift sanctions imposed after the incident in which Pyongyang has always denied involvement.

Two days ahead of the fifth anniversary of the sinking, in which 46 South Korean seamen died, the North's top military body, the National Defence Commission (NDC), condemned Seoul's steadfast insistence on the "cock-and-bull" idea that Pyongyang was responsible.

South and North Korea blocked access to their Kaesong joint industrial zone Monday after a fire broke out near a cross-border road and spread across the closely guarded frontier, officials said.

The blaze started on the North Korean side of the Demilitarized Zone (DMZ) which surrounds the border and spread quickly along the road leading to the industrial complex in the North, the South's unification ministry said.