PYONGYANG, North Korea (AP) ― South Korean weightlifters marched with their national flag at the start of an international competition hosted by bitter rival North Korea ― something of a milestone for two countries that were trading war threats this spring.

It’s the first time South Korean athletes have attended an international sports event in North Korea, government officials in Seoul said. Both countries consider themselves the only legitimate government on the Korean Peninsula, which is still technically in a state of war because the 1950-53 Korean War ended in an armistice, not a peace treaty.

The concession Thursday by North Korea at the Asian Cup and Interclub Weightlifting Championship this week comes during a mellowing in animosity as the countries pursue diplomacy.

After the war rhetoric of March and April, which North Korea linked to U.N. sanctions imposed over its February nuclear test, the Koreas have recently restored a military hotline at the border, agreed to restart a jointly run factory park shut down in April, and will have reunions this month of families separated by the war.

Many in Seoul and Washington are still wary of North Korea’s intentions, however. The North has refused to pull back from its vows to boost its nuclear weapons and missiles, and recent satellite images appear to show it is restarting a plutonium reactor.

The South Korean delegation that attended the ceremony at Ryugyong Jong Ju Yong Indoor Stadium in Pyongyang is composed of 41 athletes, sports officials and others, according to the South’s ministry for affairs with the North. They are scheduled to return to Seoul on Wednesday.

Seoul said it allowed the trip because the competition is an international match organized by the Asian weightlifting federation. North Korea also promised to guarantee the safety of the southern delegation and said South Korea’s flag could be hoisted and its national anthem played if the lifters win gold, Seoul said.

South Korean athletes last visited North Korea when a South Korean youth soccer team traveled to Pyongyang in 2008 for a friendly inter-Korean match, according to officials in Seoul.