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Top advisers to President Obama are close to a decision recommending that the self-proclaimed mastermind of the Sept. 11, 2001, terror attacks be prosecuted in a military tribunal, The Washington Post reported Friday, citing unnamed administration officials.

According to the report, the president's advisers have grown increasingly wary of bipartisan opposition to the planned civilian federal trial in New York City, mere blocks from where nearly 3,000 Americans were killed in the spectacular attack on the World Trade Center.

White House officials told Fox News that no final decision has been made. The administration has been considering tribunals for the alleged Sept. 11 attack plotters for several weeks. At issue is both the location of the planned trial and the venue.

New York Mayor Michael Bloomberg and prominent state Democrats, who initially embraced Attorney General Eric Holder's decision to try Khalid Sheikh Mohammed and four other conspirators in Manhattan, have since reversed their support for the trial in New York.

The paper said administration officials are privately bracing for backlash from disappointed liberals and some government lawyers should Obama reverse his decision to try the detainees in civilian courts.

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Officials told the Post an announcement could come soon and that they hoped to finalize their plans by March 18, when Obama leaves for a trip to Indonesia.

The matter is at the White House after Holder decided in November to transfer Mohammed and the four other accused terrorists from the prison at the U.S. naval base at Guantanamo Bay, Cuba, to New York City for civilian trials.

When opposition ballooned further into Congress and an attempted Christmas airline bombing brought massive scrutiny to Obama's terrorism policies, the administration said it would review Holder's trial decision and consider all options for a new location.

In addition to local opposition to a trial, the administration faces pressure on its goal of closing Guantanamo on another front. Republicans in Congress have proposed barring prosecutions of terrorism defendants in federal courts or in reformed military commissions located in the United States.

Republican Rep. Peter King has proposed legislation that would prevent the Obama administration from putting Mohammed and other terrorists on trial in any American community. Republican Sen. Lindsey Graham joined by about half the Senate's Republicans and a few Democrats, has made a similar proposal.

Separate from the internal trial review, the White House is in still-ongoing negotiations with lawmakers over those proposals, including how to secure funding from Congress to hold terrorism trials and to close the Guantanamo prison and replace it with another facility in the United States.

The Obama administration views civilian trials for terrorists as an important demonstration of the U.S. commitment to rule of law. Officials also have cited the numerous terrorism trials already held successfully in U.S. criminal courts.

Further, the administration argues that prosecutorial decisions are for the executive branch to make, not lawmakers.

The American Civil Liberties Union quickly launched an attack on the president Thursday night for the looming decision.

"If this stunning reversal comes to pass, President Obama will deal a death blow to his own Justice Department, not to mention American values," Executive Director Anthony Romero said.

The Associated Press contributed to this report.