The defense chiefs of South Korea and the United States on Saturday vowed to maintain strong alliance to deter potential threats from North Korea eager to arm itself with missile and nuclear weapons.

South Korean Defense Minister Kim Kwan-jin met his American counterpart Chuck Hagel on the sidelines of the Shangri-La Dialogue under way in Singapore. It was their first meeting since the Pentagon chief took office in February. 

"We have to develop the bilateral alliance so we can have joint deterrence capability that overwhelms North Korea," deputy defense chief Lim Kwan-bin quoted his boss as saying during the meeting.

The defense chiefs agreed that North Korean provocations and threats are not acceptable and the impoverished nation will only face further isolation if it continues to develop its nuclear program, he said. 

"The two sides agreed to deepen military ties to develop a joint deterrence posture in response to North Korea's nuclear and conventional weapons," Lim said. 

The two ministers had initially planned to assess the ongoing preparations for the transfer to Seoul of the wartime operational control of its forces, but the Joint Chiefs of Staff of the two countries have already agreed to maintain the current combined command structure even after the transition, he said.

Seoul and Washington have been working to set up a new command structure to maintain their combined military posture even after the current joint body is dissolved after the OPCON transfer in December 2015.

Senior military leaders of the two nations earlier have agreed to develop an alternative joint operation body that will play a role similar to that of the current South Korea-U.S. Combined Forces Command, according to officials.

Currently, South Korea retains the peacetime operational control of its forces but in wartime, its forces would automatically come under the control of the top U.S. military commander in the country.

If the change is made, South Korea's JCS Chairman will take charge of the newly created combined theater command, with the top U.S. commander in South Korea serving as his deputy commander, according to South Korean defense officials.

Calls have grown in South Korea for delaying the planned OPCON transition as tensions remain high on the Korean Peninsula after Pyongyang, which conducted its third nuclear test in February, repeatedly threatened nuclear strikes against the South and the U.S.in the recent past.

However, military leaders of the two allies have said preparations are well underway to meet the proposed transfer deadline. 

To make sure that Seoul is capable of exercising its wartime control, the allies plan to assess the South Korean military's capability and security situation on the peninsula three times prior to implementing the agreement, officials said. 

The tentative plan will be formally signed during an annual bilateral ministerial meeting scheduled in October in Seoul after working-level officials fine-tune more details in the coming months, the South Korean vice defense chief said. 

In the run-up to the scheduled transfer, Seoul has been stepping up its combat capability with an advanced missile defense system and longer ballistic missiles as the South Korean forces are supposed to play a leading role under the new command structure. 

The two Koreas remain technically at war as the 1950-53 Korean War ended in an armistice, rather than a peace treaty. About 28,500 U.S. troops are stationed in South Korea.

After their bilateral meeting, Kim and Hagel later got together with their Japanese counterpart Itsunori Onodera for discussions on ways to coordinate their policy on North Korea and expand defense ties between the nations, Seoul officials said.

The three defense leaders called on Pyongyang to discard its nuclear weapons to abide by U.N. Security Council resolutions.

"The defense chiefs supported the U.N. Security Council that calls for additional measures if North Korea conducts additional nuclear test or missile launches," Seoul's defense ministry said in a statement released after the trilateral meeting. 

The three countries also agreed to expand cooperation in anti-piracy efforts in the sea off Somalia, humanitarian aid and international disaster support as well as the global non-proliferation campaign, the ministry said. 

In addition, Kim held bilateral meetings with representatives of Indonesia, Canada and Australia to discuss ways to deepen defense ties with the regional players, it said. (Yonhap News)