Secretary-General Ban Ki-moon said he is heading to Haiti on Sunday for his second visit since the devastating earthquake to prepare for the upcoming donors conference to raise money for reconstruction.

Ban flew to Haiti on Jan. 17 -- five days after the the quake -- for a first-hand look at the widespread destruction, which included the collapse of U.N. headquarters in Port-au-Prince. He returned to New York with the bodies of Haiti mission chief Hedi Annabi and his deputy, Luiz Carlos da Costa, who were killed along with 99 other U.N. staff members.

Ban told visiting U.S. Secretary of State Hillary Clinton that during his brief visit on Sunday he plans to discuss preparations "for a successful international donors conference" with Haiti's President Rene Preval and Prime Minister Jean-Max Bellerive.

Ban and Clinton will co-chair the donors conference at U.N. headquarters on March 31.

The secretary-general thanked Clinton and President Barack Obama for the "very generous" U.N. humanitarian support to Haiti and the dispatch of U.S. military forces which "provided a very important breathing space for the U.N. ... to work properly in delivering humanitarian aid."

Clinton said she was looking forward to the donors conference.

"We will redouble our efforts and commitments so that we can make a real difference in Haiti as we move forward," she said.