The U.S. Defense Department on Tuesday said violence in Afghanistan was at an all-time high since the nine-year-old war started, and progress made by the NATO-led forces there were limited.

The assessment was made in a congressionally mandated report. It said combat incidents in Afghanistan from April 1 to Sept. 30 were up 300 percent comparing with 2007 figures. It also noted a 55 percent rise over the previous quarter in "kinetic events," including direct and indirect fire, surface-to-air fire and exploded, found or cleared roadside bombs.

The report attributes the rise to the increase in coalition and Afghan forces and their expansion into new areas, a dramatically accelerated pace of operations and a spike in incidents during the September parliamentary elections.

U.S. President Barack Obama ordered the deployment of 30,000 additional troops to Afghanistan late last year, but even with the new troops influx, the Pentagon report found progress across Afghanistan "uneven," with only modest gains in security, governance and development in key areas.

The report indicated the number of Afghans rating their security situation as "bad" is the highest since the nationwide survey began in September 2008.

The report cites growth in Afghan security forces as the "most promising" area of progress, and notes incremental improvement in security and socio-economic development.

The increase in Afghan security forces "is the key to the transition," a Defense official who briefed the press Tuesday about the report said on condition of anonymity, noting that both the Afghan army and police have been ahead of their recruiting goals since July.

The report, submitted every 180 days to the Congress, tracks government, economic and military activity to assess coalition success in reaching President Barack Obama's goal of disrupting, dismantling and defeating al-Qaida in Afghanistan.

The United States is set to start the drawdown of combat forces in Afghanistan in July, and NATO has set 2014 as a goal to complete the security handover to Afghan forces.