US President Barack Obama and his South Korean counterpart Park Geun-hye urged the Democratic People 's Republic of Korea (DPRK) Friday to stop further threatening actions.

Obama arrived here Friday afternoon as a second leg of his four- nation Asian tour after staying in Japan for three days. His week- long tour will also take him to Malaysia and the Philippines.

The two heads of state agreed to maintain close cooperation in all issues on the DPRK to achieve the joint goal, and the goal of the international community as well, of complete, verifiable and irreversible denuclearization of the DPRK in a peaceful manner.

The two allies reaffirmed that UN Security Council censured the DPRK's ballistic missile launch, which violated four resolutions of the council, demanding Pyongyang not conduct further provocation that will violate international obligations and pledges.

They urged the DPRK to stop "doing further threatening actions, " saying the two countries will cooperate with the international community to secure a complete and transparent implementation of all Security Council resolutions related to the DPRK.

South Korea's Defense Ministry said increased activity was detected at the DPRK's main nuclear test site after the North's threatened to conduct a "new form of nuclear test" last month.

Pyongyang fired around 90 short-range and self-propelled artillery shells in late February and March before test-firing medium-range Rodong missiles which had landed in waters off Japan.

Obama and Park decided to review timing of the transfer of wartime operational control of allied forces, citing a change in the region's security environment caused by what they call " lasting missile and nuclear threats from the DPRK."

The wartime command of combined forces was initially supposed to be transferred to South Korea in 2007, but was postponed twice to December 2015. Seoul has asked Washington to delay the transfer following Pyongyang's third nuclear test in February last year.