Steve Bannon has refused to answer questions on his time as a Trump adviser on the advice of his lawyer, who phoned the White House during a House Intelligence Committee hearing.

Key points: Steve Bannon refused to answer questions posed by the Intelligence Committee about his time at the White House

Steve Bannon refused to answer questions posed by the Intelligence Committee about his time at the White House Bannon's lawyer relayed the questions in real time to the White House, which instructed him not to answer

Bannon's lawyer relayed the questions in real time to the White House, which instructed him not to answer Bannon also struck a deal to avoid a grand jury in Robert Mueller's investigation into Russian interference

The move has been labelled a "gag order", with Mr Bannon refusing to answer numerous questions after his lawyer relayed them in real time to the White House during the House of Representatives Intelligence Committee interview.

Separately, President Donald Trump's former chief strategist has also struck a deal to be interviewed by US special counsel Robert Mueller's team rather than appearing before a grand jury, after being subpoenaed to testify in his probe of alleged Russian meddling in the 2016 US presidential election, according to CNN.

An interview with prosecutors would allow Mr Bannon to have a lawyer present during his appearance, as lawyers are not permitted in grand jury rooms.

Committee issues congressional subpoena

As the House Intelligence Committee's questioning moved from Mr Trump's election campaign to Mr Bannon's time in the White House, his lawyer William Burck called with White House lawyers to ask whether his client could answer the questions.

He was told not to discuss his work on the transition to, or in, the White House.

Committee members sought answers around Mr Bannon's time working for Mr Trump, including the President's thinking when he fired FBI director James Comey, but Mr Bannon refused to answer a broad array of questions about that crucial period.

As a result the chairman, Republican Devin Nunes, issued a congressional subpoena, spokesman Jack Langer said.

A White House official said the White House counsel's office had a conversation last week with committee counsel about Mr Bannon's testimony and was told the questions were expected to be about the election campaign.

The official said the White House offered to send a lawyer to attend the interview and was told the move was not necessary.

It is unclear who Mr Burck was communicating with in the White House.

Mr Burck is also representing top White House lawyer Don McGahn in Mr Mueller's investigation into contacts between the Trump campaign and Russia.

Adam Schiff, the committee's top Democrat, said Mr Bannon's refusal to answer questions from the panel "can't stand" and went far beyond other witnesses who have declined to answer specific questions.

He said the committee expects to have Mr Bannon return for more questioning.

"This was effectively a gag order by the White House preventing this witness from answering almost any question concerning his time in the administration and many questions even after he left the administration," Mr Schiff said.

White House press secretary Sarah Sanders said: "As with all congressional inquiries touching upon the White House, Congress must consult with the White House prior to obtaining confidential material.

"This is part of a judicially recognised process that goes back decades."

But Mr Trump's chief of staff John Kelly later told Fox News the White House did not tell Mr Bannon to invoke executive privilege during the hearing.

Bannon negotiates private Mueller interview

Robert Mueller is investigating allegations Russia tried to influence the 2016 election. ( AP: Evan Vucci, file )

In a separate investigation into Russian interference in the 2016 presidential election, led by Mr Mueller, Mr Bannon will meet with investigators for an interview instead of appearing before a grand jury.

Mr Bannon was subpoenaed to give evidence in Mr Mueller's investigation, but this may have been a negotiating tactic that prompted Mr Bannon to agree to a sit-down with prosecutors rather than appearing before the grand jury.

A person familiar with the issue confirmed the interview and said Mr Bannon is expected to cooperate with Mr Mueller.

It is unclear when the interview might occur.

A spokesman for Mueller declined to comment on the CNN report.

Bannon was a key Trump adviser

Mr Bannon was a close adviser during Mr Trump's campaign and in his first months in office, but he was fired from his White House job in August as the President sought to bring more order to his staff operations.

Earlier this month, Mr Trump attacked Mr Bannon for comments he made to Michael Wolff, the author of a book highly critical of the President and his family.

They included scathing remarks about Donald Trump Jr, the President's eldest son, for meeting during the campaign with a Russian lawyer who was said to have damaging information on Democratic candidate Hillary Clinton.

AP/Reuters