(For more on Afghanistan, click on [ID:nAFPAK])
* Violence reaches record levels since Taliban's ousting
* Attacks becoming increasingly brazen
* Taliban forces have problems of their own
KABUL, Aug 10 (Reuters) - The Taliban have advanced out of traditional strongholds in Afghanistan's south and east, gaining momentum as they moved into the north and west, the top U.S. and NATO commander said in an interview on Monday.
U.S. Army General Stanley McChrystal, who will soon present an assessment of the war, said the resurgent Taliban have forced a change of tactics on foreign forces and warned that record casualty figures would remain high for some months.
"It's a very aggressive enemy right now," McChrystal told The Wall Street Journal newspaper (online.wsj.com/) in an interview in Kabul. "We've got to stop their momentum, stop their initiative. It's hard work."
Violence across Afghanistan this year had already reached its worst levels since the Taliban were ousted by U.S.-led Afghan forces in 2001 and escalated dramatically after major offensives were launched in southern Helmand province in July.
Attacks have also become increasingly brazen, with suicide bombers and gunmen attacking government buildings and Afghan and foreign military targets in the east and south.
At least three Afghan police and two civilians were killed in a strike by gunmen and suicide bombers on government buildings near Kabul on Monday, 10 days before a presidential election.
With thousands of U.S. Marines and British soldiers aiming to push Taliban fighters out of populated areas in Helmand, July quickly became the war's deadliest month for foreign troops.
At least 41 U.S. troops were killed, easily surpassing the previous highest monthly toll of 26 in September last year. At least 71 foreign troops in total were killed in July.
Britain has suffered its worst ground combat casualties in a generation, with 22 killed in July, raising questions about whether its troops are adequately supplied, how long they will be in Afghanistan, or whether they should be there at all.
INSURGENTS FACE OWN PROBLEMS
The Journal said McChrystal's remarks showed he believed the Taliban were "winning" and had gained "the upper hand", but McChrystal's aides said the paper overstated the general's views, and he believed the insurgents had difficulties of their own.
"He did say that NATO forces are facing an aggressive enemy employing complex tactics, but during the course of the interview he also observed that insurgents in Afghanistan face their own problems in terms of popularity, cohesiveness and ability to sustain morale and fighting capacity," said McChrystal's spokesman, Lieutenant Colonel Edward Sholtis.
There are now about 101,000 foreign troops in Afghanistan, with U.S. numbers at about 62,000. Washington has been pouring in thousands of extra troops this year, in part to help secure Aug. 20 presidential and provincial council elections.
Washington plans to increase the number of its troops to about 68,000 by year's end, more than double the 32,000 it had stationed in Afghanistan at the end of 2008. McChrystal may ask for more after he submits a review of strategy in coming weeks.
McChrystal wants a "very significant expansion" of the Afghan army and police, the Journal said.
He planned to push more troops into Kandahar, the spiritual home of the Taliban adjacent to Helmand, and to send troops from sparsely populated areas to more densely settled areas. (Writing by Paul Tait; Editing by David Fox)