WASHINGTON - Afghan citizens feel less secure now than at any other time in the recent past, as civilian casualties rise to their highest level in seven years, according to Pentagon.

In a report Friday to Congress covering war developments since December, the Pentagon cited progress in developing more capable Afghan security forces 15 years after a US-led invasion toppled the Taliban government. But it also said public opinion surveys indicate Afghans don't feel better protected.

It said that while the Afghan government remains in control of "all major population centres and key lines of communication," a "resilient insurgency" continues to destabilise the nation.

A survey of Afghan citizens indicated that perceptions of security among them are at an all-time low, with 42 percent saying security is worse now than during the period of Taliban rule from 1996 to 2001.

A UN assistance mission in Afghanistan has been tracking civilian casualties since 2009. It says the rate rose to a historic high in 2015 and continued to rise in the first half of this year, as fighting and suicide attacks by insurgents have moved into more populated areas.

Earlier this month, the White House gave the military more authority to conduct offensives against the Taliban, at the request of US military commanders.

President Barack Obama had vowed to reduce US troop levels in Afghanistan from the present 9,800 to 5,500 before he leaves office in January. With circumstances as they are, however, it is not clear whether that plan will be carried out.