The White House also said in the statement that chief of staff John Kelly "will immediately set up a meeting with the FBI, DoJ and DNI together with congressional leaders to review highly classified and other information they have requested".
House Intelligence Chairman Devin Nunes has complained that the Justice Department and Rosenstein specifically have stonewalled him on requests for documents related to the Russian Federation probe, including details of the FBI's use of an informant.
Sanders had said earlier that Deputy Attorney General Rod Rosenstein, FBI Director Christopher Wray and Director of National Intelligence Dan Coats were expected to gather at the White House on Monday afternoon for a discussion aimed at addressing congressional requests.
The Justice Department said the White House had signed off on its letter, but Nunes wasn't satisfied, and continued to pressure the department. A Washington Post story Friday, which did not name Halper, said the informant aided the Russian Federation investigation both before and after Mueller's appointment in May 2017.
Rep. Adam Schiff of California, the senior Democrat on the House Intelligence Committee, has called Trump's claim of an embedded spy "nonsense".
In the latest salvo from Trump's administration and his Republican Party, the president assailed former Central Intelligence Agency chief John Brennan, a strident critic, as having initiated the investigation.
The Justice Department agreed on Monday to investigate "any irregularities" in Federal Bureau of Investigation tactics related to President Donald Trump's 2016 campaign after Trump questioned whether an Federal Bureau of Investigation informant had been planted into his political organization.
Stocks rebound as US-China trade war 'on hold'
Media reports suggested that the USA was offering to swap a ZTE rescue for an end to proposed Chinese tariffs on US farm products. A week ago, Trump tweeted that he was working with Chinese President Xi Jinping to put ZTE "back in business, fast".
Trump lawyer Rudy Giuliani said Sunday that Mueller, who has already issued 22 indictments, wants to finish the investigation by the beginning of September to avoid overlapping with election campaigns.
A White House official told Axios that, "Recommending outside policy experts for roles within the administration is a pretty typical and routine action for White House officials". She said the officials will "review highly classified and other information they have requested", but did not provide additional detail.
The Justice Department in March launched an investigation into how the FBI gained a warrant to surveil Page.
But in this case, he said, he can not understand the Justice Department's opposition to releasing the name.
There's no evidence that the FBI installed an informant or spy in Trump's campaign, though the bureau did rely on an informant who was in contact with Trump associates, according to two US officials who spoke on condition of anonymity.
Responding to Trump's earlier claims that the Obama administration could have been spying on his campaign, former Director of National Intelligence James Clapper said that the president's claim was "hyperbole", but added that if USA intelligence had been spying on his campaign, it would be a "good thing". It's unclear what documents the department agreed to turn over to Congress.