"The withdrawal is going well," General Kenneth Ekman, US commander for Africa, told reporters in Abidjan.

"It is ahead of schedule and this is because of the excellent coordination that we have had with our Nigerien military counterparts," said Ekman, who heads up the US Africa Command Africom.

"I expect that we will be complete with the withdrawal by early August, well ahead of the 15 September mutually agreed deadline,"

The United States pulled out of a base in the Niger capital Niamey in early July, but another 200 US soldiers remain at the Agadez drone base in the north of the country.

US troops were part of an international effort to suppress jihadists forces that regularly strike across the region.

But the Niger military leaders who seized power in a coup a year ago in March told US and French forces to quit the country.

"The consequences for regional security are very concerning," Ekman said.

"I've been here speaking to your military and government leaders -- we share the same concerns about the violent extremist threat that is growing and increasingly threatening the countries around the Sahel."

He said the United States would continue to work with Ivory Coast security forces, but he denied media reports that the US military was looking to build a base in Odienne, in the north of the country.

US forces recently took part in the "Flintlock" military exercises in Ivory Coast that involved hundreds of soldiers from Western and African countries.