SEOUL, Aug 23 (Reuters) - The U.S. special envoy for North Korea was due to meet his South Korean counterpart on Monday, as the two allies look for ways to entice Pyongyang back to talks over its nuclear weapons and ballistic missile programmes. Sung Kim arrived in Seoul on Saturday for a four-day visit. He met with Foreign Minister Chung Eui-yong at the minister"s residence on Sunday, where they discussed ways for a speedy resumption of the peace process on the Korean peninsula, a foreign ministry official said. On Monday Kim will meet with his South Korean counterpart, Noh Kyu-duk, and on Tuesday with Russian Deputy Foreign Minister Igor Morgulov in Seoul. The visit comes as a brief thaw in inter-Korean relations in July gave way to a new standoff over U.S.-South Korean military exercises that North Korea has warned could trigger a security crisis. read more The nine-day exercise began on Aug. 16, with silence so far from North Korean state media despite fears that the country could conduct a missile test or take other actions to underscore its disapproval. read more North Korea has said it is open to diplomacy, but that the American overtures appear hollow while "hostile acts" such as the drills continue U.S. President Joe Biden"s administration has said it will explore diplomacy to achieve North Korean denuclearisation, but shown no willingness to ease sanctions.