Washington  - The situation in Afghanistan is deteriorating and the country's Taliban and al-Qaeda insurgency are gaining strength, the top US commander for the region warned Wednesday as the US prepares to send thousands more troops to Afghanistan.

General David Petraeus, head of US Central Command, said in congressional testimony that insurgents had expanded their control over the southern and eastern parts of the country.

Their success was being fuelled by drug money, the ability of insurgents to move freely across the Afghan-Pakistan border and growing public anger with the inability of the Afghan government to improve the lot of its people.

"The Taliban and other insurgent groups are growing in strength and waging an increasingly violent campaign against coalition forces and the Afghan state," Petraeus told the Senate's Armed Services Committee.

"Reversing the cycle of violence, defeating the extremist insurgencies in these countries, and eliminating safe havens for al- Qaeda and other trans-national extremist organizations require a sustained, substantial commitment," he said.

President Barack Obama laid out a revised strategy for Afghanistan on Friday, vowing to dismantle al-Qaeda's operations in the region. The administration is sending extra 21,000 troops and Obama has also promised more civilian and diplomatic personnel to aid Afghanistan's economic recovery. (dpa)