US President Barack Obama delivers a statement on the Afghanistan-Pakistan Annual Review from the White House Briefing Room in Washington Dec 16, 2010. Obama on Thursday said the United States and its allies are making important progress in the war in Afghanistan but that the gains in many areas are fragile and reversible. [Photo/Agencies]

WASHINGTON - At the height of the war he escalated, President Barack Obama on Thursday declared major progress in turning back America's enemies in Afghanistan and Pakistan, promising US troops will start coming home in July. Even so, he predicted four more years of combat, soberly warning the gains could slip away.

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Speaking to a nation weary of war, Obama said his year-old strategy was succeeding in its two primary military objectives: degrading the leadership of the Pakistani-based al-Qaida terrorists who attacked the United States, and breaking the strength of the Taliban militants who once provided them haven in Afghanistan.

Yet his internal war review underscored huge challenges, too, from the terrorist sanctuaries in Pakistan to the desperate need for Afghanistan's government to offer basic services to its people and rid itself of corruption.

Put together, Obama's words and the report's findings underscore that his war strategy is here to stay.

On the issue that touches home most to millions of Americans, Obama stuck with his pledge that some US forces would return home in July. But the scope of that withdrawal is expected to modest and its pace is unknown, as the transition to Afghan forces taking control of their nation is expected to last through 2014.

"I want to be clear: This continues to be a very difficult endeavor," Obama said from his White House podium, flanked by fellow leaders of the government. "But I can report that, thanks to the extraordinary service of our troops and civilians on the ground, we are on track to achieve our goals."

He then made a point to remind the nation what those goals are, a sign of how long this war has gone on - launched nearly a decade ago, and often overshadowed during that time by the Iraq war and the US recession.

"We will never waver from our goal of disrupting, dismantling and ultimately defeating al-Qaida," Obama said of the terror network that plotted the Sept 11, 2001, attacks from Afghanistan. The Taliban, which allied itself with al-Qaida, has been a resurgent force in Afghanistan, prompting Obama to mount a military offensive.

There are roughly 100,000 US troops in Afghanistan, a record level, as well as 40,000 from NATO allies. More than 2,100 US forces have been killed in the war, including at least 480 this year, the highest to date.

Obama's upbeat assessment - "in pursuit of our core goal, we are seeing significant progress" - comes as separate US national intelligence estimates of Afghanistan and Pakistan paint bleak pictures of security conditions inside Afghanistan and of Pakistan's willingness to rout militants on its side of the border.

Obama left the stage after his comments and turned it over to leaders of the US military and diplomatic efforts, who found themselves fending off criticism that the presidential portrait was too rosy.

Defense secretary Robert Gates, who recently returned from Afghanistan, said, "The sense of progress among those closest to the fight is palpable." Secretary of State Hillary Rodham Clinton said there were no "rosy-scenario people in the leadership of this administration. ... This has been a very, very hard-nosed review."

At the heart of the US strategy is an accelerated mission to train and expand Afghanistan's security forces so they can defend themselves. "This is really the path out for everybody," Gates said.

As for the pace of the US withdrawal, Gates added: "The answer is, we don't know at this point."

While US, NATO and Afghan forces have pushed insurgents from their strongholds in southern Afghanistan and are aggressively going after militants in the east, the Taliban have opened new fronts in the west and the north where security has been deteriorating for more than two years.

Ahead of Obama's comments, scores of anti-war protesters massed outside the White House under the first notable snowfall of Washington's winter. They held signs and white banners with doves and some clung to the gate of the White House complex as police officers watched to make sure they didn't attempt to scale it.

Unlike the US role in the war in Iraq, which Obama opposed and is drawing to a close, the Afghan conflict has become a defining part of his presidency. He sees it as vital to American security and has nearly tripled US forces there. Yet only a minority of Americans now support the war in Afghanistan, and the degree to which Obama is seen as having offered credible, effective leadership on it will affect his re-election bid.

"I'm well aware of the popular concern, and I understand it," Clinton said of public attitudes about the war. "But I don't think leaders - and certainly this president - will not make decisions, that are matters of life and death and the future security of our nation, based on polling."

A defining issue in the months ahead will be the degree to which the United States can get Pakistan's cooperation in rooting out the terrorists within its borders. Obama, who has significantly escalated the scope of the war and always centered that effort on defeating al-Qaida, claimed his most progress to date.

"In short, al-Qaida is hunkered down," the president said. "It will take time to ultimately defeat al-Qaida, and it remains a ruthless and resilient enemy bent on attacking our country. But make no mistake. We are going to remain relentless in disrupting and dismantling that terrorist organization."

Yet in Pakistan, he said that despite more coordination "progress has not come fast enough. So we will continue to insist to Pakistani leaders that terrorist safe havens within their borders must be dealt with."

And in Afghanistan, Obama said, the need for better political and economic progress is urgent.

In Brussels, Belgium, NATO Secretary-General Anders Fogh Rasmussen said the review showed that the US strategy was sound and that the allies had the necessary resources to carry it out.

"Now we have to consolidate those gains and make them irreversible. This is a challenging task, but we are determined to see it through," Fogh Rasmussen said.