The governments of Kenya and Uganda are expressing disappointment after Thursday's decision by the United States to leave the two East African allies off the list of countries eligible for $1 billion in extra U.S. aid.

The United States on Thursday did not say why some developing countries like Kenya and Uganda, which have a long history of receiving U.S. aid, were left off the list of 16 countries eligible for assistance from the Millennium Challenge Account. The two countries will continue to receive their regular U.S. assistance, but will not share in the extra money this year.

Members of the Millennium Challenge board of directors said that they had to be extremely selective, because President Bush created the account last year offering aid only to those countries that met certain criteria.

Board members had to consider both the past and current performance of candidate countries in the areas of governance, financial accountability and the promotion of economic freedom.

The eight African countries that made this year's list are Benin, Cape Verde, Ghana, Lesotho, Madagascar, Mali, Mozambique and Senegal.

Observers say Kenya probably failed to make the cut because the country is still grappling with official corruption. Uganda, observers say, is seen as having a tightly-controlled system of governance that does not allow dissent or opposition.

In Kenya, President Mwai Kibaki, who took power in democratic elections 15 months ago, acknowledged that the country is still suffering from the culture of graft that marked the 25-year rule of his predecessor, Daniel arap Moi.

However, Mr. Kibaki said that his government is making every effort to eliminate corruption for good.

?My government has declared total war against corruption,? he said. ?The Kenyan anti-corruption authority has been revitalized and the passing of the Public Officers Ethics Act will ensure that public officers account for their wealth. These measures and others will ensure that hard work gets just reward and that there exists a level playing ground devoid of undue advantages.?

In Kampala, Ugandan government spokesman Nsaba Buturo insisted that President Yoweri Museveni is also committed to change. Mr. Buturo said that the Ugandan leader is working to end the country's one-party political system and to allow multi-party elections.

?As a matter of fact, we now have six parties that are newly formed,? he said. ?We are in talks with opposition groups and all this is being done to get ready for a return to multi-partyism. Opening up of political space is something this country is committed to and is happening.?

The board of directors for the Millennium Challenge Account says it will encourage and work closely with countries that have not met eligibility requirements this year, but are making good faith efforts to meet them in the future.

President Bush is expected to ask Congress for approval for $2.5 billion to be put into the account next year, more than twice the amount of this year's budget.