Newly declassified intelligence files are shedding fresh light on the disturbing warnings U.S. officials received about Osama bin Laden and Al Qaeda years before the September 11 attacks.

The CIA released 71 declassified presidential intelligence documents on Friday, marking the 25th anniversary of 9/11. The records show that officials in both the Bill Clinton and George W. Bush administrations were repeatedly warned that bin Laden wanted to strike inside the United States — including through hijackings and possible attacks involving aircraft.

One of the most alarming warnings came on Sept. 10, 1998.

According to the newly released material, intelligence prepared for Clinton’s Presidential Daily Brief said bin Laden’s preferred option was to strike America on its own soil and included information suggesting terrorists could “fly an explosive-packed airplane into a US city.”

The intelligence did not identify a specific target, date or operational plan, and officials reportedly had questions about the reliability of some of the sources. But the possibility of an aircraft being used in an attack was clearly being discussed nearly three years before 9/11.

Another chilling document dated Dec. 4, 1998, carried the headline “Bin Ladin Preparing To Hijack US Aircraft.”

The brief said members of bin Laden’s network had received hijacking training and reported that two suspected operatives had allegedly managed to evade security checks during what was described as a trial run at an unidentified New York airport.

The intelligence suggested bin Laden may have been considering a hijacking before Ramadan began later that month.

The warnings kept coming.

A July 1998 intelligence report said U.S. officials had received several reports — though from sources considered highly questionable — suggesting bin Laden was preparing an attack inside the United States.

By February 2000, intelligence officials were examining a seized manifesto that reportedly identified possible targets including the Statue of Liberty in New York and the Eiffel Tower in Paris.

Analysts were also tracking threats involving Washington, D.C., including concerns about attacks against government buildings and public locations.

Then came one of the most infamous pre-9/11 intelligence reports.

In the summer of 2001, President George W. Bush received a briefing warning that bin Laden was “determined to strike in US.”

The document said Al Qaeda members had lived in or traveled through the United States and that the organization appeared to maintain a support network capable of assisting attacks.

It also cited suspicious activity that investigators believed could be consistent with preparations for hijackings or other terrorist operations. By August 2001, the FBI was reportedly conducting roughly 70 investigations across the country involving suspected links to bin Laden.

Just weeks later, on Sept. 11, 2001, Al Qaeda terrorists hijacked four commercial passenger jets.

Two were flown into the World Trade Center towers in New York City, another struck the Pentagon and a fourth crashed in Pennsylvania after passengers and crew fought back.

Nearly 3,000 people were killed.

The newly released documents do not establish that either administration knew the specific 9/11 plot was coming or possessed intelligence precise enough to stop it.

The bipartisan 9/11 Commission previously concluded that the government suffered from major intelligence-sharing failures and failed to fully imagine how terrorists might use hijacked passenger aircraft as weapons. The new records largely reinforce that established history while revealing more of the warnings senior officials were receiving.

Bush later told the 9/11 Commission that he had not received actionable intelligence that would have allowed his administration to prevent the attacks.

Clinton also defended his administration’s efforts against bin Laden after leaving office, saying in a 2006 interview that he had tried — and failed — to eliminate the Al Qaeda leader.

The newly released files show intelligence agencies were also concerned about even more terrifying possibilities.

Officials investigated reports that bin Laden could be trying to acquire nuclear, chemical or biological weapons. One 1999 assessment warned that if he obtained a chemical or biological weapon, analysts believed he would likely be willing to use it.

Other reports examined possible bombing plots against U.S. government buildings, including claims about a potential attack on FBI headquarters in Washington. Some of those warnings were considered unreliable and never materialized.

The intelligence also tracked bin Laden’s interest in securing the release of Omar Abdel-Rahman, the radical cleric known as the “Blind Sheikh,” who was imprisoned in the United States following his conviction in a terrorist conspiracy connected to plots against New York landmarks.

The CIA released the documents as the country marked a quarter-century since the attacks.

CIA Director John Ratcliffe described the disclosure as an act of transparency intended to honor those who were killed, calling it the agency’s largest release of presidential briefing material connected to 9/11.

The release came as former National Security Adviser Condoleezza Rice publicly expressed remorse over the government’s failure to prevent the attacks.

“Those of us in authority on that day did not see the nature of the danger in time to prevent the attack of 9/11,” Rice said during the anniversary commemorations.

The newly opened files paint a disturbing picture: years before America suffered the deadliest terrorist attack in its history, intelligence officials already knew bin Laden wanted to bring his war directly onto U.S. soil.

What they did not know was exactly when, where or how he would strike.