Taliban militants are gathering across Afghanistan in preparation for a possible takeover of the country by force as U.S. and NATO troops exit over the next few months, the United Nations has warned.

The insurgents continue to be "closely aligned” with al-Qaida and are massing "forces around key provincial capitals and district centers, allowing them to remain poised to launch attacks,” the report released Wednesday said.

"The Taliban’s intent appears to be to continue to strengthen its military position as leverage. It believes that it can achieve all of its objectives by negotiation, or if necessary, by force.”