Ban met at U.N. headquarters with South Korean Foreign Minister Kim Sung-hwan to discuss peace and security in the Korean Peninsula.
Ban said he was concerned about severe food and nutrition problems in North Korea, the United Nations' news service reports.
The U.S. State Department announced last week that North Korea placed a moratorium on long-range missile launches, nuclear tests and other nuclear-related material in exchange for food assistance from the United States.
Robert King, U.S. special envoy for North Korean human rights issues, said Thursday there was progress on food assistance. He told reporters in Beijing that he was "satisfied" with the outcome of bilateral talks but no details had been formalized.
Victoria Nuland, a spokeswoman for the U.S. State Department, said the White House was "cautiously optimistic" that the U.S. government would be able to deliver nutritional assistance to the North Koreans.
Ban's meeting with the South Korean foreign minister comes ahead of a nuclear security summit scheduled for March 26 in Seoul.