Washington: US President Barack Obama on Tuesday said that it would be "very difficult" over the next two years for al-Qaida to stage a spectacular terror attack on the scale of the September 11 strikes in 2001.
Obama said that given America`s open society, it would always be vulnerable, but argued that as a result of a stepped-up US campaign which had "decimated" al-Qaida`s leadership, the country was safer.
"But for them to be able to mount something that is a big project with a lot of financing, that is very difficult for them to do now," Obama said in an interview with Yahoo.com and ABC News.
"They are still dangerous, they are still our number one enemy, we have got to make sure that we don`t let up.
"But I think we are in a position over the next couple of years, if we stay on it, it is going to be very difficult for them to mount the kinds of spectacular attacks that we saw on 9/11."
Obama spoke days after a top al-Qaida suspect, US-born cleric Anwar al-Awlaqi, was killed in a suspected US drone strike in Yemen, becoming the latest member of the group to die in a volley of intensified US attacks.
Administration officials confided on Friday that at least 23 senior extremist Islamic leadership figures had been killed or captured, in US or allied operations in Pakistan, Somalia, Yemen and elsewhere since August 2009.
The most spectacular coup for the campaign was the killing of al-Qaida chief Osama bin Laden in a US special forces raid on his hideout inside Pakistan in May.