In the declaration, the North agree to permanently close its Tongchang-ri engine test site and missile launch pad.
Tuesday's meeting between the South's President Moon Jae-in and the North's leader Kim Jong Un is their third so far this year.
The nuclear-armed North invaded its neighbour in 1950, starting the Korean War.
He said international guarantees would be "appropriate" along with US offers.
The two leaders will meet in the North Korean capital to discuss "practical measures to denuclearise" the peninsula.
'All parties concerned should... show more sincerity and flexibility, instead of being capricious and put the blame on others'
Trump has touted the summit with Kim in Singapore as a historic breakthrough, but both sides have since complained of stalling progres
The remains flown to Osan on Friday are expected to be sent to Hawaii for forensic identification.
The women, in their 20s, have denied murdering Kim Jong Un's estranged half-brother as he waited for a flight to Macau. They face death by hanging if found...
Seoul is also pushing for the release of six South Koreans held by Pyongyang.
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