这两个密切相关的问题--平壤核拆除的速度和制裁救济的时间表--是首脑会议的主要议题。

The Wall Street Journal
Trump to North Korea: Nuclear dismantlement must happen before sanctions lifted
Published: Apr 23, 2018 2:43 a.m. ET

White House says ‘sky is the limit’ if Kim denuclearizes
KCNA via Reuters
North Korean leader Kim Jong Un announced Saturday that his country would close its nuclear test site and suspend long-range missile tests.

By Michael R. Gordon，Jonathan Cheng，Michael C. Bender

President Donald Trump will urge North Korea to act quickly to dismantle its nuclear arsenal when he meets North Korean leader Kim Jong Un and isn’t willing to grant Pyongyang substantial sanctions relief in return for a freeze of its nuclear and missile tests, administration officials said.
Those two closely related questions — the pace of Pyongyang’s nuclear dismantlement and the timetable for sanctions relief — stand to be the major issues of the summit.
“When the president says that he will not make the mistakes of the past, that means the U.S. will not be making substantial concessions, such as lifting sanctions, until North Korea has substantially dismantled its nuclear programs,” a senior Trump administration official said Sunday.
“If North Korea is willing to move quickly to denuclearize, then the sky is the limit. All sorts of good things can happen,” the official added.