Talks might be held Sunday on repatriating remains of American soldiers killed in the 1950s conflict.
Trump says North Korea is no longer a nuclear threat,' but summit the Singapore agreement does not spell out terms of ending Pyongyang's nuclear program.
South Korea supports 'big framework,' but looks to understand Trump decision to end joint Washington-Seoul military exercises.
Visit comes as US is battling opioid abuse emergency that is killing more than 60,000 people annually.
Tough negotiations lie ahead as North Korea has rejected unilateral disarmament, calling instead for complete denuclearization of the Korean peninsula.
Details of pact are still being worked out, but US news accounts say that as part of accord ZTE could pay additional penalties beyond $1.2 billion fine.
But US president acknowledges that eventual outcome of his talks with Kim Jong-un is uncertain, with Pyongyang yet to agree to dismantle its nuclear arsenal and the permanent denuclearization of Korean peninsula.
State media commentary rejects notion that international sanctions brought about diplomatic thaw.
Ceremonial head of state Kim Yong Nam is planning three-day visit as games open Friday.
'Wall Street Journal' quotes US leader saying he already has a 'good relationship' with Pyongyang leader, but Trump says he believes he would have such relationship at some point in future.
UN envoy praises Seoul-Pyongyang talks on Olympics, but says US not 'letting up on pressure' against North Korea.
US president says a Pyongyang missile test landing near the American territory 'would have been both catastrophic and unacceptable'.
Trump criticizes China following Pyongyang's missile launch on Friday.
Designating the world's most populous country in same category as Iran, North Korea, Syria.
Two-day meeting would occur at US president's estate along Atlantic Ocean.
Warning comes after US Secretary of State Kerry blasts North Korea over its nuclear and missile tests.