WASHINGTON — The Trump White House is nearing completion of an order that would direct the Pentagon to bring future Islamic State detainees to the Guantanamo Bay prison, despite warnings from national security officials and legal scholars that doing so risks undermining the effort to combat the group, according to administration officials and a draft executive order obtained by The New York Times.

White House officials have detailed their thinking about a new detainee policy in an evolving series of drafts of an executive order being circulated among national security officials for comment. While previous versions have shown that the draft has undergone many changes — including dropping language about reviving CIA prisons — the plan to add Islamic State detainees to the Guantánamo population has remained constant.

The latest version of the draft, which circulated this week, would direct Defense Secretary Jim Mattis to use Guantanamo to detain suspected members of “Al Qaeda, the Taliban, and associated forces, including individuals and networks associated with the Islamic State.’’

The White House has kept similar language in the draft order despite warnings from career government national security officials that carrying out its plan would give federal judges an opportunity to reject the executive branch’s theory that the war against the Islamic State is legal, even though Congress never explicitly authorized it. The issue could arise when reviewing an inevitable habeas corpus lawsuit filed by the Islamic State.

The Obama administration first argued in late summer 2014 that the Islamic State was part of the existing armed conflict that Congress authorized in 2001 against Al Qaeda and the Taliban. But while the Islamic State got its start as Al Qaeda’s affiliate in Iraq more than a decade ago, that theory is disputed because the two groups later split and went to war with each other.

“It raises huge legal risks,’’ said Jack Goldsmith, a Harvard Law School professor and former senior Justice Department official in the Bush administration. “If a judge says the Sept. 11 authorization does not cover such a detention, it would not only make that detention unlawful, it would weaken the legal basis for the entire war against the Islamic State.’’

The Times reported Feb. 4 that the White House had limited the draft order so that it focused on carrying out President Trump’s vow to keep the Guantánamo prison open and use it for newly captured detainees. That draft of the order dropped the ideas of reopening CIA prisons and permitting interrogators to use harsher techniques than those now allowed in the Army Field Manual.

That report was based on accounts by people familiar with a version that circulated last week. But a new draft order circulated this week, titled “Protecting America Through Lawful Detention of Terrorist and Other Designated Enemy Elements,’’ includes some revisions. The latest version, unlike the previous one, explicitly revokes President Obama’s January 2009 executive order directing the government to close the prison by January 2010, a deadline it failed to meet.

The revised text also dropped references to revitalizing the use of the military commissions system at Guantanamo for prosecuting terrorism suspects, and instead focused exclusively on detention policy — like its directive to use the prison to detain captured Islamic State suspects without trial.