“At the request of the Nigerian government, the United States will discontinue its training of a Nigerian Army battalion,” the US Embassy in Abuja said in a statement.
Two initial phases of training had already been completed between April and August this year which provided “previously untrained civilian personnel with basic soldiering skills,” it added.
A third session had been planned “with the intent of developing the battalion into a unit with advanced infantry skills”.
“We regret premature termination of this training, as it was to be the first in a larger planned project that would have trained additional units with the goal of helping the Nigerian Army build capacity to counter Boko Haram,” it said.
There was no immediate response from the Nigerian government.
The US was one of several foreign powers who offered intelligence and surveillance assistance to Nigeria to help find the 219 schoolgirls who have been held hostage by Boko Haram since mid-April.
But with the teenagers apparently no nearer being found and the five-year Islamist insurgency increasing in intensity and violence, diplomatic ties have become strained.
Last month Nigeria’s ambassador to Washington, Adebowale Adefuye, claimed that his government was dissatisfied with the “scope, nature and content” of US support.
In particular, he accused Washington of failing to provide the “lethal” weapons needed to deliver “a killer punch” to the militants, including attack helicopters.
That prompted a strongly worded response from the State Department, which mentioned the training of the new battalion.
The State Department said there were “ongoing concerns” about the Nigerian military’s human rights record and its ability to protect civilians during operations.
Nigeria’s military – West Africa’s largest – and the government have faced a raft of similar accusations from rights groups and this weekend from the country’s leading Muslim organisation.
The JNI said the government was not doing enough to prevent civilian deaths in the wake of a double suicide bombing and gun attack on Kano’s central mosque that left at least 120 dead on Friday.