WASHINGTON (AP) — Law enforcement officials decided not to call all airlines directly on Monday to tell them an important name had been added to the government's "no-fly" list, even as investigators pursued the man they suspected was the Times Square bomber.

Emirates airlines apparently didn't notice the notification from the Transportation Security Administration that there was an addition to the list, and Faisal Shahzad boarded a Mideast-bound jetliner before federal authorities pulled him off and arrested him. On Wednesday, the government issued a new requirement for airlines to check the no-fly list more often, a move aimed at closing that security gap in future cases of terror suspects.

But officials could have called all the airlines themselves in such a critical situation — they've done it before.

This would have put Shahzad on the radar of the carriers, and it could have prevented him from being able to board the Emirates plane headed for Dubai.

The FBI asked the TSA not to make the calls, according to an administration official who spoke on condition of anonymity in order to discuss the ongoing investigation. The FBI did let the TSA call a few domestic air carriers, which did not include Emirates.

According to the Obama administration, the airline appeared to drop the ball on Monday by not consulting an updated list when the Times Square suspect purchased his ticket. A post-9/11 requirement that airlines provide Customs and Border Protection officials with lists of passengers 30 minutes before departure kept Shahzad from leaving the country.

Obama administration officials say this is why the aviation security system has multiple layers. Emirates airlines officials did not respond to requests for comment about their role in the security lapse.

On Wednesday, the government issued a new requirement: Airlines must check updates to the no-fly list within two hours of being notified of changes.

Previously, the airlines have had to check for updates every 24 hours. If they don't comply with the new policy, they could face penalties, a Homeland Security official said.

This is the latest policy change for one of the government's best-known counterterrorism tools, a list that is constantly updated based on terror threats — but one that is also known for inconveniencing innocent travelers when they are held up at airport security because their names are similar to those on the list. The list was never intended to be the country's last line of defense against terrorism. But whenever there is an aviation security-related incident, the process gets refined.

Intelligence officials have always been concerned about sharing sensitive information widely, such as the name of a suspect. Some airlines are partially owned by their governments, and law enforcement officials could have thought that notifying all of the airlines to be on the lookout for Shahzad could jeopardize the case.

The FBI would not comment on the decision. "We don't discuss specific operations or investigative techniques," FBI spokesman Richard Kolko said.

Rep. Peter King, R-N.Y., called the decision not to make the calls a mistake in judgment and "clearly wrong."

Kip Hawley, a former TSA administrator, said officials have made such calls in critical situations before.

"When somebody comes across as an expedited no-fly, that means pick up the phone, don't send an e-mail," he said.

Hawley was the head of TSA when intelligence officials unraveled a 2006 terror plot in which al-Qaida operatives planned to blow up U.S.-bound airliners using liquid explosives. As soon as Hawley and others were aware that names would be added to the no-fly list, they prepared to pick up the phone and call people directly, he said. He would not say who specifically was called during the 2006 plot because that information is operationally sensitive.

The last change to the watch-listing process came after the attempted Christmas Day airliner bombing by a man whose name was not on the no-fly list despite the availability of disparate pieces of intelligence on the bomber and the plot. Since then intelligence analysts have added thousands of names to the list based on up-to-date threat information with the hope of not letting another terrorist on an airplane.

Then Monday happened. Amid a fast-paced terror investigation, law enforcement officials put the name of the man prosecutors say tried to blow up an SUV in Times Square on the no-fly list early Monday afternoon. The Homeland Security Department sent a notification to airlines that the watch list had been updated and that they should work off of the latest version. Because Shahzad was able to board the plane, the government believes Emirates airlines did not consult the updated no fly list when he bought his one-way ticket in cash, just hours before the flight was scheduled to leave.

Customs and Border Protection officials spotted Shahzad's name on the passenger list and recognized him as the bombing suspect they were looking for when Shahzad was in his seat and the plane was preparing to leave the gate. Customs officials knew to look for him because of updates to the no-fly list made earlier in the day.

"You don't have to have a silver-bullet strategy," White House spokesman Robert Gibbs said Wednesday. "So the system is set up so that a series of checks are provided that prevented this person from flying."

The changes announced Wednesday do not go far enough, Sen. Charles Schumer, D-N.Y. said. The administration should require that airlines flag passengers who pay for tickets with cash as well, he said.

Schumer also said matching names to watch lists in the commercial aviation sector should be up to the government, not airlines.

The government agrees. It has planned to take over the responsibility, but the transition has taken longer than expected. The new program is almost fully implemented for domestic airlines and is months away from beginning with international carriers.

As for the airline in Monday's case, it released this statement Wednesday:

"Emirates fully cooperated with and responded immediately to all local and federal authorities on all matters related to its flight EK 202 (New York-Dubai, 3rd May) where a passenger was removed from the aircraft by U.S. law enforcement officials. Emirates is in full compliance with all passenger check-in procedures in the U.S. and works closely with both the Transport Security Administration (TSA) and the U.S. Customs and Border Protection (CBP) agencies to update security watch lists on a regular and timely basis."