Home Secretary John Reid, hosting an informal meeting of European Union interior Ministers in London, said the terror threat was Europe-wide and needed to be tackled on an international level.
"What's clear to all of us is that we face a persistent and very real threat across Europe," he said.
The meeting was held as a mid-air "passenger disturbance" on a Washington-bound flight from Heathrow forced the pilot to declare a security emergency.
The United Airlines flight was escorted into Boston by two F15 fighter jets, amid claims of a confrontation between a female passenger and flight crew.
Reports that she had been carrying matches, Vaseline, a screwdriver and a note about al Qaida were later denied, but the incident started a major security alert.
Later an FBI spokeswoman in Boston said the woman was in police custody for allegedly "interfering with a flight crew".
Massachusetts Governor Mitt Romney said the 59-year-old, from the state of Vermont, became so claustrophobic and upset that she needed to be restrained.
In London, Mr Reid refused to be drawn on reported comments by Deputy Prime Minister John Prescott that some of the 24 suspects being held in connection with the alleged plot to bomb airliners could face only minor charges.
But he said police appeared to believe that there was material of a "substantial nature" emerging from inquiries.
Among the measures discussed at the meeting were proposals to make the Internet a "hostile environment" for terrorists.
Other proposals included a requirement to provide similar data on airline passengers on flights in Europe, to that required by the United States and Canadian authorities for passengers travelling to their countries.
Ministers considered "positive profiling" of passengers, carried out before flights, based on "biometric identifiers" such as iris scans or fingerprints.
The ministers also freed up 350,000 euros (£237,000) from the EU budget for research into detecting liquid explosives which the alleged plotters were said to be planning to use.
In closed court hearings last night, anti-terror detectives applied for more time to question 23 of the 24 suspects in custody over the alleged plot.
In each case, officers were presenting evidence to a district judge for him to decide whether it was sufficient to warrant their further detention.
Last night specialist officers were searching woodland in High Wycombe, Bucks, for traces of explosives or explosive tests.
There were claims yesterday that Britain was seeking the fast-track extradition of another suspect in the case, who is being held in Pakistan.
Rashid Rauf, a British citizen and brother of one of those held in the UK, is alleged by the Pakistani authorities to have been a key player in the plot.
Rauf's relatives in Pakistan were reported to have insisted he was harmless. The Home Office refused to say whether it had requested his extradition.