Nigeria's President Goodluck Jonathan on Friday cancelled a visit to the hometown of more than 200 schoolgirls who were kidnapped by Islamic militants, sparking fresh criticism of his handling of the crisis.
A senior government official told AFP that Jonathan's trip to remote Chibok in Borno state "was on (the president's) schedule up to this morning" but the visit had been scrapped.
No reason was given but security concerns were reportedly blamed.
Instead of visiting Chibok, Jonathan is now due to head direct to a security summit in Paris on Saturday to discuss the Boko Haram threat to regional stability.
Jonathan's administration has been widely criticised for its slow response to the kidnapping on April 14, which saw 276 girls abducted by militants. A total of 223 are still missing.
But they were forced to act in the face of a social media campaign and street protests that won global support and attracted the attention of foreign powers, who have now sent specialist teams to help in the rescue effort.
The cancellation prompted immediate criticism on social networks and others who claim the president has shown indifference to the mass abduction.
"If, as the commander-in-chief of the armed forces, he is afraid to visit Chibok because of security fears, he is simply telling the hapless people in the northeast that he cannot protect them and they should resign themselves to their fate," said Debo Adeniran, of the Coalition Against Corrupt Leaders pressure group.
In the United States, which has sent drones and surveillance aircraft, the chairman of the Senate Committee on Foreign Relations said Nigeria had been "tragically and unacceptably slow" to tackle the crisis.
"I have called on President (Goodluck) Jonathan to demonstrate the leadership his nation is demanding," Democratic senator Robert Menendez said.
Others raised the Nigerian military's human rights record after well-documented claims of abuses carried out by soldiers, including arbitrary detention and summary execution of civilians.
The Principal Deputy Assistant Secretary of State for African Affairs, Robert Jackson, told senators: "Resolving this crisis is now one of the highest priorities of the US government."
- Lawmakers back special powers -
A state of emergency was imposed in three northeastern states worst affected by the violence on May 14 last year. Special powers were extended for a further six months in November.
Jonathan requested the extension on Tuesday, calling the security situation in Borno, Yobe and Adamawa "daunting."
More than 2,000 have been killed this year alone, most of them civilians, in increasing violence across Muslim-majority northern Nigeria that has seen churches, schools and entire villages attacked.