ISTANBUL - The top U.S. and NATO commander in Afghanistan said on Thursday the security situation remained serious but was no longer deteriorating, offering a more upbeat assessment than other U.S. military and intelligence officials.

Dire warnings from General Stanley McChrystal and other commanders last summer about the worsening outlook prompted U.S. President Barack Obama to order the deployment of 30,000 additional troops to battle a resurgent Taliban.

I believe the situation in Afghanistan is serious. I do not say now that I think it's deteriorating. I think and I said that last summer, and I believed that that was correct. I feel differently now, McChrystal told reporters in Istanbul on the sidelines of a meeting of NATO defence ministers.

I'm not prepared to say that we have turned the corner, he added. But ... I think we have made significant progress in setting conditions in 2009 and ... we'll make real progress in 2010.

So far, 4,500 of the 30,000 additional U.S. troops ordered by Obama have arrived in Afghanistan, to join the nearly 70,000 there before the surge began in December. The Pentagon said levels were expected to reach 98,000 by the end of September.

Other NATO member-states and allies have about 45,000 troops there and have promised to send thousands more.

ROADSIDE BOMBS

Pentagon officials said on Thursday U.S. pledges to help allies counter a surge in roadside bombings had been a factor in winning the promises to send more soldiers.
McChrystal touted an imminent offensive on a Taliban enclave in southern Afghanistan by thousands of Marines as the next step in the counterinsurgency campaign.

He said the operation showed the people of Afghanistan that we are expanding security, and served as a warning to the Taliban that the partnership between U.S., NATO and Afghan forces was maturing.

The planning is in great shape... I'm very confident and very impressed with where they are, particularly the partnership, McChrystal said of the planned offensive on Marjah, a Taliban-controlled town in Helmand province.

He said the operation would get under way relatively soon.

McChrystal's improved assessment appeared at odds with warnings earlier this week by other top officials that the insurgency was growing more lethal and spreading its reach.

Dennis Blair, the U.S. director of national intelligence, told lawmakers that Afghanistan's Taliban insurgency has become increasingly dangerous and destabilizing.

The director of the U.S. Defense Intelligence Agency, Lieutenant General Ronald Burgess, warned U.S. troops faced an increasingly capable insurgency.

Admiral Mike Mullen, chairman of the U.S. military's Joint Chiefs of Staff, told lawmakers that Taliban insurgents have a growing influence in most of Afghanistan's provinces.

WAR OF PERCEPTIONS

McChrystal said he had not seen Mullen's testimony.

What I will tell you is I think that the Taliban are making a significant effort to expand their influence. So is the government of Afghanistan now, aided by us, McChrystal said.

He attributed his more upbeat view to factors including better cooperation between NATO and Afghan forces and impressions during travels in Afghanistan and meetings with local leaders.

What I see and what I feel gives me that sense, he said. This is all a war of perceptions. This is not a physical war in terms of how many people you kill or how much ground you capture ... This is all in the minds of the participants.

U.S. officials held out the possibility of providing equipment such as armoured vehicles to NATO allies to help protect their troops against roadside bombs and other threats.

Pentagon press secretary Geoff Morrell said U.S. Defense Secretary Robert Gates was committed to sharing our best practices, our lessons learned, with all of the troop-contributing nations within the confines of the law -- whatever laws would prohibit sharing of certain sensitive information.

(Reporting by Adam Entous; editing by Andrew Roche)