(Adds quotes from Nadler, background)
WASHINGTON, July 24 (Reuters) - The U.S. House of Representatives Judiciary Committee will go to court this week to enforce a subpoena of former White House counsel Don McGahn and will also ask for grand jury material related to former Special Counsel Robert Mueller's Russia probe, the panel's chairman said on Wednesday.
Democratic Representative Jerrold Nadler, speaking to reporters after Mueller's testimony before his panel and the House Intelligence Committee, said the court actions could come on Thursday or Friday.
U.S. President Donald Trump told McGahn in May to defy a subpoena to testify before Congress about the Russia investigation. Nadler said at the time that Trump was trying to block damaging testimony about the Republican president's obstruction of justice.
Mueller emphasized on Wednesday that he had not exonerated Trump of obstruction of justice, but his long-awaited congressional testimony did little to add momentum to any Democratic impeachment ambitions.
Nadler indicated that Democrats, frustrated by Trump's stonewalling of congressional probes, would press ahead with the investigations.
"The very next step, either tomorrow or Friday, is we’re going into court to ask for the grand jury material and to enforce the subpoena against Mr. McGahn," Nadler said on Wednesday.
"That’s particularly important because the excuses ... that the White House gives for McGahn not testifying ... are the same excuses for all the other fact witnesses, and if we break that, we’ll break the logjam."
McGahn cooperated with Mueller's team during its two-year probe, telling investigators that Trump had called him several times in June 2017, urging him to direct the Justice Department to remove Mueller because of conflicts of interest.
He did not carry out that order or a later one to dispute news reports about the incidents, according to the special counsel's findings released in a redacted two-volume report in April.
Trump, in an interview with ABC News in June, rejected McGahn's account and said the lawyer "may have been confused" during his testimony as part of the Mueller investigation.
(Reporting by Susan Cornwell; Additional reporting by Eric Beech; Writing by Mohammad Zargham; Editing by David Alexander and Peter Cooney)