WASHINGTON — The acting director of national intelligence will not testify before Congress this week or immediately hand over a whistle-blower complaint to lawmakers, escalating a standoff between Capitol Hill and leaders of the intelligence agencies.

The Democratic chairman of the House Intelligence Committee, Representative Adam B. Schiff of California, demanded in a cryptic letter on Friday that Joseph Maguire, the acting director of national intelligence, turn over a whistle-blower complaint made to the inspector general for the intelligence agencies.

[Update: Watchdog refuses to detail whistle-blower complaint about Trump.]

Mr. Schiff asked in his letter whether the underlying conduct involved “the president or those around him.” But Mr. Schiff has said he cannot discuss the content of the complaint, and it is difficult to assess because its nature is not publicly known. Other lawmakers said they did not know the complaint’s details.

“The committee’s position is clear — the acting D.N.I. can either provide the complaint as required under the law,” Mr. Schiff said, “or he will be required to come before the committee to tell the public why he is not following the clear letter of the law, including whether the White House or the attorney general are directing him to do so.”