SEOUL - The Republic of Korea's presidential Blue House said Saturday that the country would consult with the United States on the revision of the bilateral missile guideline to increase the payload of the indigenous ballistic missiles.The ROK President Moon Jae-in ordered his top security advisor Chung Eui-yong to consult with the US side on the launch of negotiations about the amendment of the ROK-US missile guideline, senior presidential press secretary Yoon Young-chan told a press briefing.It followed the DPRK's announcement of its second test-firing of an intercontinental ballistic missile (ICBM), which flew about 1,000 km and was lofted as high as over 3,700 km.Chung held a telephone conversation with his US counterpart H.R. McMaster at about 3 am local time Saturday (1800 GMT on Friday) to propose the revised missile guideline.McMaster sent the US agreement on the negotiation at around 10:30 am local time, according to the Blue House of The ROK.Moon's press secretary said the negotiation would focus on an increased payload, rather than an extended range, adding that the two countries would launch the negotiation as early as possible.The bilateral missile guideline was first adopted in 1979 to set ceilings on the range of the ROK's homegrown ballistic missiles at 180 km and the payload at 500 kg in return for the US transfer of missile technology to the ROK.Under the revised guidelines, the maximum range and payload were extended in 2001 to 300 km and 500 kg, and in 2012 to 800 km and 500 kg respectively.Local media speculations said the ROK would demand the maximum payload of its ballistic missiles be extended to 1 ton.