The defense chiefs of South Korea and the United States revealed their differences on the transfer of wartime operational control of South Korean troops from Washington to Seoul. 

South Korean Defense Minister Suh Wook and his U.S. counterpart, Mark Esper, held their annual Security Consultative Meeting(SCM) at the Pentagon in Washington on Wednesday. 

Suh said at the start of the talks that the allies will work together to prepare for a combined defense system led by South Korean troops by meeting the conditions for the OPCON transfer early. 

On the other hand, Esper said in his opening remarks that fully meeting all the conditions for the transition of operational control to a South Korean commander will take time. 

In a joint statement issued after the meeting, the defense chiefs said they discussed the direction of the transfer including the test for the Full Operational Capability(FOC). The FOC test is one of the crucial steps to verify if Seoul is on course to meet the conditions for the transition.

The two sides, however, failed to come to terms on details, including when they will hold the test. 

Esper and Suh had been scheduled to hold a joint news conference after the talks, but the U.S. reportedly called it off at the last minute, raising speculation that the two sides had differences on pending issues.