Washington (CNN) -- North Korea's agreement to halt portions of its nuclear and missile programs and accept the return of nuclear inspectors is a "modest step in the right direction," U.S. Secretary of State Hillary Clinton said Friday.
Clinton said, however, that the United States will be watching North Korea closely and judging the country's leaders by their actions in the coming weeks and months.
North Korea last week announced it would freeze its nuclear and missile tests, along with uranium enrichment programs, and allow the return of U.N. nuclear inspectors in exchange for 240,000 metric tons of food aid from the United States.
North Korea has suffered famines and widespread malnutrition during the past two decades -- thanks to its dysfunctional economy and international sanctions. Other countries and international groups have repeatedly stepped in with food aid to alleviate the situation.
The United States suspended shipments of food aid to North Korea in 2009 amid tensions over Pyongyang's nuclear program and concerns that the supplies were not reaching those most in need.
Clinton spoke after meeting in Washington with South Korean Foreign Minister Kim Sung-hwan, who called the North Korean agreement "a meaningful first step" toward resolving the North Korean nuclear issue.
Kim said "faithful implementation" of the measures to which North Korea agreed -- the moratorium on nuclear activities and the return of the inspectors -- was important going forward.
The timing of the food aid is unclear.
Robert King, the U.S. special envoy for North Korean human rights issues, said the administrative details have been resolved, but officials are still working on details.
King, who on Thursday wrapped up two days of talks with officials from Pyongyang, said he is optimistic that the food aid will find its way to those in need in North Korea.
The initial deal last week to resume the deliveries came after the the two countries revived negotiations that had stalled after the death in December of the longtime North Korean leader Kim Jong Il.
The talks this week were intended to finalize points like what ports will be used to dock incoming ships, how the distribution of the food will be monitored and which nongovernmental organizations will be involved.
U.S. officials cautiously welcomed the agreement last week in hopes of a new era in relations with North Korea and a resumption of multilateral talks aimed at the denuclearization of the Korean peninsula.
But Pyongyang has stepped up its rhetoric against the South Korean president, Lee Myung-bak, and his government since Kim Jong Un took over from his father, Kim Jong Il, as North Korean leader.
Earlier this week, North Korean television aired footage of a military unit carrying out live-fire drills in sight of a South Korean island.
It showed tanks repositioning and an artillery machine being prepared, overlooking waters that have seen a number of violent incidents over the years.
Li Gum-chol, a North Korean deputy commander, threatened to engulf Seoul in a "sea of flames" in retaliation for U.S.-South Korean joint military drills taking place on the peninsula. North Korea has condemned the annual drills as provocation.