United Nations Secretary-General Ban Ki-moon was planning to visit areas devastated by Pakistan's worst floods Sunday, a UN official said.
"He is arriving today," spokesman Ishrat Rizvi said in Islamabad. "Later in the day he will visit the areas affected by the floods and see himself the destruction."
Ban is also expected to meet UN officials and Pakistani leaders, dpa reported.
The UN has appealed for 460 million dollars to assist millions of refugees from the floods that have killed around 1,400 people. But international response to the appeal has been slow.
Donors have pledged barely 20 per cent of the funds that the UN says are required to supply food, shelter, medicine and clean water to the 6 million people in immediate need.
A total of 20 million people were left homeless, according to Pakistani government.
Floods that ravaged large parts of the north-western province of Khyber-Pakhtunkhwa and central Pakistan are now submerging more areas in southern province of Sindh, where hundreds of thousands of people are on move.
More than 700,000 houses and over 3.2 million hectares of standing crops have been destroyed or damaged.