* Junta boss Djibo says he will fight corruption and abuses
* He says famine threatens millions in all parts of Niger
* Vow to restore democracy, but no date
By David Lewis and Abdoulaye Massalatchi
NIAMEY, Feb 28 (Reuters) - Millions of people are threatened by famine in Niger, the new military ruler said on Sunday in a message that contrasted starkly with his predecessor's reluctance to talk about food shortages.
Major Salou Djibo, who ousted President Mamadou Tandja in a coup on Feb. 18, also said the junta was committed to tackling impunity, corruption and the abuse of power during an unspecified transitional period before promised elections.
The coup, as well as subsequent promises to clear up Niger's politics and business, have been well received in the West African nation.
But the international community, which criticised the coup, fears that a return to civilian rule could be delayed by an open-ended attempt to attack corruption.
The coup took place as aid agencies and the government were bracing for food shortages and acute malnutrition after poor rains last year. Niger suffered similar problems in 2005 but Tandja's government delayed publicly calling for help.
Addressing the nation on state television on Sunday, Djibo said all means were urgently being deployed to tackle the famine, which "threatens the existence of millions of Nigeriens in virtually all regions".
Although the largely desert nation is better prepared to tackle the crisis than it was in 2005, aid workers say that it was difficult to talk openly about food shortages under Tandja because the issue was so sensitive.
Privately many hope that this will now change, though few have gone so far as to say Niger may suffer a famine.
An official report leaked to a Nigerien newspaper in January said about 7.8 million of the population of 15 million would face food insecurity this year, contradicting public assurances made by the then government.
Djibo again vowed to restore democracy. But he gave no date for the elections -- something that many in the international community want to see before restoring aid that was cut off when Tandja extended his rule last year.
A constitutional referendum awarded Tandja three more years in power. But it also raised the tensions that led to the coup, and has fuelled widespread distrust of the political class.
Djibo stressed on Sunday that the junta would carry out its plan to "clean up" the political and economic situation, notably by "fighting impunity, corruption and abuse of power".
The junta, which is known as the Supreme Council for the Restoration of Democracy, has said that investors in the Niger's uranium and oil industries have been reassured.
But Djibo also vowed to bring transparency to those sectors, which have come under scrutiny in local media after allegations of widespread corruption in the awarding of contracts.