WASHINGTON (NYTIMES) - President Donald Trump's newly appointed national security adviser has told his staff that Muslims who commit terrorist acts are perverting their religion, rejecting a key ideological view of other senior Trump advisers and signaling a potentially more moderate approach to the Islamic world.

The adviser, Lt-Gen H.R. McMaster, told the staff of the National Security Council on Thursday (Feb 23) in his first "all hands" staff meeting that the label "radical Islamic terrorism" was not helpful because terrorists are "un-Islamic," according to people who were in the meeting.

That is a repudiation of the language regularly used by both the president and McMaster's predecessor Michael T. Flynn, who resigned last week after admitting that he had misled Vice-President Mike Pence and other officials about a phone call with a Russian diplomat.

It is also a sign that McMaster, a veteran of the Iraq War known for his sense of history and independent streak, might move the council away from the ideologically charged views of Flynn, who was also a three-star army general before retiring.

Wearing his army uniform, McMaster spoke to a group that has been rattled and deeply demoralised after weeks of upheaval, following a haphazard transition from the Obama administration and amid the questions about links to Russia, which swiftly engulfed Flynn.

McMaster, several officials said, has been vocal about his views on dealing with Islamic militancy, including with Trump, who on Monday described him as "a man of tremendous talent, tremendous experience."

McMaster got the job after Trump's first choice, Robert Harward, a retired navy vice-admiral, turned it down.

Within a day of his appointment on Monday, McMaster was popping into offices to introduce himself to the council's professional staff members. The staff members, many of them holdovers from the Obama administration, felt viewed with suspicion by Trump's team and shut out of the policymaking process, according to current and former officials.

In his language, McMaster is closer to the positions of former Presidents Barack Obama and George W. Bush. Both took pains to separate acts of terrorism from Islamic teaching, in part because they argued that the United States needed the help of Muslim allies to hunt down terrorists.

"This is very much a repudiation of his new boss' lexicon and worldview," said William McCants, a senior fellow at the Brookings Institution and author of "The ISIS Apocalypse."

"McMaster, like Obama, is someone who was in positions of leadership and thought the United States should not play into the jihadi propaganda that this is a religious war," McCants said.

"There is a deep hunger for McMaster's view in the interagency," he added, referring to the process by which the State Department, Pentagon and other agencies funnel recommendations through the National Security Council.

"The fact that he has made himself the champion of this view makes people realise they have an advocate to express dissenting opinions."

But McCants and others cautioned that McMaster's views would not necessarily be the final word in a White House where Trump and several of his top advisers view Islam in deeply xenophobic terms.

Some aides, including the president's chief strategist Stephen Bannon, have warned of a looming existential clash between Islam and the Judeo-Christian world.

Bannon and Stephen Miller, another senior adviser with anti-Islamic views, have close ties to Trump and walk-in privileges in the Oval Office. McMaster, 54, has neither.

Known for challenging his superiors, McMaster was nearly passed over for the rank of brigadier general in 2007, until Gen David Petraeus, who used his counter-insurgency strategy in Iraq, and Robert Gates, then defence secretary, rallied support for him.

The schisms within the administration could be aired publicly if the Senate Armed Services Committee exercises a right to hold a confirmation hearing for McMaster.

Although the post of national security adviser does not require Senate confirmation, senators must approve his retention of his three-star rank in a new position.

Senator John McCain, the committee's chairman and a strong supporter of McMaster, has not said whether he wants to hold a hearing.