While administration officials typically travel to the Capitol building to brief lawmakers on national security issues, on Wednesday the entire Senate will hop on a bus to the White House where four top officials will meet with them simultaneously. The same four officials will then go to Capitol Hill to brief the entire House at 5 p.m. EDT (2100 GMT), a senior House aide said.
"I hope and expect that it is worth the time of the trip and that we'll hear things we don't know, and that we'll come out of it better informed. We'll see," said Senator Chris Coons, a Democratic member of the Senate Foreign Relations Committee.
The meeting was set for one day after a North Korean holiday on Tuesday marking the 85th anniversary of the founding of its army. While North Korea has in the past staged nuclear or missile tests to mark the day, this year it conducted a major live-fire exercise.
It also comes as Trump tries to put the best face on his first 100 days in office, a period in which the president signed a variety of executive orders to roll back Democratic policies but has been defined by an absence of any major legislative achievements.
Lawmakers, including some of Trump's fellow Republicans, also have said the early months of his presidency have been marked by a lack of communication with Congress, partly because the administration has been slow to fill key posts and partly because Trump has been slow to develop policy positions.
Although the White House has downplayed the importance of Saturday's 100-day anniversary, Trump will mark the day with a rally in Pennsylvania.