The U.S.-led United Nations Command (UNC) and the Democratic People's Republic of Korea (DPRK) on Friday discussed forming a joint assessment group to assess the cause of the armistice violations that led to the sinking of a South Korean warship in March, the UNC said in a statement.

The two sides held a second round of colonel-level meeting earlier Friday in the truce village of Panmunjom, which lasted for one hour and forty minutes.

The statement said, seeking to comply with the United Nations Security Council president's intent, the UNC proposed to set up a Joint Assessment Group (JAG) to assess the cause of the armistice violations that led to the sinking of the South Korean navy frigate Cheonan.

"The two sides exchanged ideas and further details for convening a JAG in accordance with the Armistice Agreement," it added.

The Armistice Agreement was signed at the end of the 1950-53 Korean war, and has since left the two sides technically at war.

The statement said the "centerpiece of the meeting" was "a requirement by the UNC" that the DPRK's military "demonstrate their intent to comply with the UN Security Council president's statement." However, it did not mention the DPRK side's response.

The UNC also notified the DPRK of the upcoming U.S.-South Korea joint military exercise "Ulchi Freedom Guardian", according to the statement.

The UNC announced in the same day that the annual Ulchi Freedom Guardian exercise will take place in the period from Aug. 16 to Aug. 26.

The two sides also tentatively agreed to hold another colonel- level meeting on July 29, the statement said.

The UNC and the DPRK held a similar meeting on July 15, the first after the Cheonan incident took place, during which the two sides agreed to convene general-grade talks over the warship sinking.

The U.S.-led UNC, which said it is charged with the enforcement and maintenance of the Armistice Agreement, has convened 16 rounds of talks with the DPRK since the General Officer Talks forum between the two sides launched in 1998. However, the DPRK always insists that the "UNC" was unjust, and the so-called "United Nations troops" is just U.S. troops stationed in South Korea.

On March 26, the South Korean frigate Cheonan, with 104 crew members aboard, went down off the South Korean island of Baekryeong off the west coast due to an unexplained explosion, killing 46 sailors.

Seoul formally referred the case of warship sinking to the UNSC on June 4 after it concluded that the 1,200-ton warship was torpedoed by the DPRK. But the DPRK denied any involvement and asked the UNSC to act to help find the truth of the incident.

The UN Security Council adopted a presidential statement on the Cheonan issue early this month, condemning the attack on the warship while stopping short of directly naming a culprit.