This is how today's America treats its democratizing allies in Africa - BBC:
Nigeria's ambassador to the US has criticised Washington for refusing to sell his government "lethal" weapons to fight militant Islamists.
Nigeria needed support to deliver the "killer punch", not "light jabs" against the Boko Haram group, Adebowale Ibidapo Adefuye said.
His comments came as the militants seized the north-eastern Mahia town.
The US has previously ruled out heavily arming the Nigerian military because of its alleged poor human rights record.
Meanwhile, Nigeria's President Goodluck Jonathan has formally declared himself as the governing People's Democratic Party's candidate (PDP) presidential candidate for February's election at a colourful ceremony in the capital, Abuja.
He called for a minute of silence for the 46 teenage boys who were killed in Monday's suicide bombing at a school in Potiskum town in Yobe, one of the three north-eastern states under a state of emergency because of Boko Haram's insurgency.
The attack has highlighted the depth of the crisis escalating in the north-east, the BBC's Nigeria correspondent Will Ross reports.
But the politicians of all parties appear more focused on the pursuit of power in oil-rich Nigeria and that is playing right into the hands of Boko Haram, he says.
Government soldiers have been accused by rights groups of carrying out many atrocities, including torturing and executing suspects.
US laws ban the sale of lethal weapons to countries whose military are accused of gross human rights abuses.