U.N. Secretary General Kofi Annan will attend a conference in Jakarta on Thursday to coordinate donation pledges to the countries affected by the deadly tsunamis in south Asia. Annan confirmed he will fly to the region and attend the conference in an interview Saturday with ABC News. He said the catastrophe in which 140,000 have been confirmed dead was the largest disaster the U.N. has dealt with in its history. Annan said he met this week with the ambassadors of the 12 countries affected. But he said he's not sure the U.N. yet understands the "sheer vastness" of the devastation. The secretary general added that the outpouring of compassion from the world thus far "has been, perhaps, one of the most generous responses that I have seen". In the week since the tsunamis struck, more money has been given than was given for all the humanitarian appeals the U.N. issued in 2004, he said in the interview, which will be aired Sunday.