KABUL, Afghanistan – President Barack Obama told Americans Tuesday that after more than a decade of wars in Iraq and Afghanistan, the nation "can see the light of a new day."

The remarks came just hours after he and Afghan President Hamid Karzai put their signatures to a far-reaching pact that will govern U.S. support for Afghanistan after U.S. combat forces are gone at the end of 2014.

Speaking early Wednesday morning local time from Bagram Air Base, a year after U.S. Navy SEALs killed al-Qaida founder Osama bin Laden, Obama said the United States is prepared to shift into a limited support role in the region after combat troops leave in 2014 and can begin to "emerge from a decade of conflict abroad and economic crisis at home."

"This time of war began in Afghanistan, and this is where it will end," Obama said an election-year speech that invoked the Sept. 11, 2001, terrorist attacks.

However, just hours after Obama departed, as many as six suicide bombers early Wednesday attacked a sprawling, heavily guarded compound on the eastern edge of downtown Kabul where international contractors are housed, police and witnesses said.

One attacker detonated his explosives outside the entrance to the Green Village on the Jalalabad Road, while others appeared to have penetrated the walled facility, sparking a ferocious gunbattle, they said. Independent Tolo TV broadcast video of the scene showing the bodies of dead and wounded lying on the highway amid the smoldering wreckage of vehicles. A witness, who asked not to be identified, said by telephone that he'd counted at least six dead.

In his remarks, Obama said, "… the tide has turned. We broke the Taliban's momentum," Obama said. "We've built strong Afghan security forces. We devastated al-Qaida's leadership, taking out over 20 of their top 30 leaders.

"And one year ago, from a base here in Afghanistan, our troops launched the operation that killed Osama bin Laden. The goal that I set – to defeat al-Qaida, and deny it a chance to rebuild – is within reach."

Obama said the administration has been in direct talks with Taliban members and that they "can be a part of this future if they break with al-Qaida, renounce violence, and abide by Afghan laws." He said many members have indicated an interest in reconciliation and that "a path to peace is now set before them."

"Those who refuse to walk it will face strong Afghan security forces, backed by the United States and our allies," he said.

The president left Afghanistan soon after delivering his speech.

Obama and Karzai had signed their agreement hours earlier, in front of Afghan and U.S. flags at the presidential palace. Karzai appeared to be in an ebullient mood, offering profuse thanks to the negotiators, including U.S. Ambassador Ryan Crocker.

After the signing, Obama addressed U.S. troops at Bagram, crediting them with blunting the Taliban, driving al-Qaida out of Afghanistan and decimating its ranks. But he warned that the conflict wasn't yet over.

"There's going to be heartbreak and pain and difficulty ahead," he told the 3,200 service members gathered at a hangar at the base. "But there's a light on the horizon because of the sacrifices you've made."

And in a remark that drew loud applause, he noted that it was a year ago that "we were able to finally bring Osama bin Laden to justice."

"That could have only happened because each and every one of you, in your own way, were doing your jobs," he said. "Each and every one of you – without a lot of fanfare, without a lot of fuss – you did your jobs."

A report released Tuesday by the Pentagon detailed the gains in Afghanistan. It noted that so far this year, enemy attacks are down 16 percent, and said recent allied efforts "seriously degraded the insurgency's ability to mount a major offensive" this year.

Other parts of the report, though, were less certain about progress. It noted continuing "long-term and acute challenges," that the "Taliban-led insurgency and its al-Qaida affiliates still operate with impunity from sanctuaries in Pakistan," and that "the Afghan government continues to face widespread corruption that limits its effectiveness and legitimacy and bolsters insurgent messaging."

Obama's visit came one year after U.S. special forces, flying from Afghanistan, burst into the Pakistan hideout of bin Laden and shot him dead. Senior White House officials acknowledged that the trip fell on the anniversary, but said the timing was driven by the desire of both presidents to have the strategic partnership agreement signed, in Afghanistan, before a NATO summit scheduled for Chicago later this month.

Republicans have criticized Obama for using the bin Laden raid in a campaign ad that also questioned whether Mitt Romney would have made the same call. Though the president is generally off-limits while traveling overseas, Oklahoma Republican Sen. Jim Inhofe accused him of politicizing the war in Afghanistan.

"Clearly this trip is campaign related," Inhofe said in a statement released just after Obama signed the agreement. "We've seen recently that President Obama has visited college campuses in an attempt to win back the support of that age group since he has lost it over the last three years. Similarly, this trip to Afghanistan is an attempt to shore up his national security credentials."

Obama's trip, his third to Afghanistan, began in secrecy to ensure strict security just two weeks after insurgent attacks penetrated the security rings of Kabul and three provincial capitals. But word that Obama was coming leaked to Afghan news media Tuesday evening, hours before he arrived, igniting furious denials by the U.S. Embassy, the White House and the presidential palace.

Obama landed at 10:20 p.m. at Bagram, the largest U.S. military base in the country, just north of Kabul. He helicoptered into the city to the fortress-like presidential palace, where he joined Karzai for the signing ceremony. The growl of prowling helicopter gunships echoed across Kabul's nighttime sky.

The text of the new agreement had been kept secret since it was initialed on April 22 by Ambassador Crocker and Karzai's national security adviser, Rangin Spanta.

The nine-page pact comprises a preamble and seven provisions covering all facets of the future relationship, from a U.S. vow to help defend Afghanistan against al-Qaida and other threats, to Kabul's commitment to "inclusive and pluralistic democratic governance, including free, fair and transparent elections."

White House officials said the only post-2014 U.S. presence would be for training and counterterrorism and that there would be no U.S. bases. The pact binds the sides to close defense cooperation to bolster Afghanistan's security, "combat al-Qaida and its affiliates," and enhance Afghanistan's ability to defend itself. The sides are to negotiate a separate bilateral security agreement governing the number of U.S. troops and Pentagon civilians to remain in Afghanistan after 2014 to train Afghan forces and to provide them with intelligence and logistics support.

The United States and its NATO allies are in the midst of transferring security responsibilities to Afghan forces, a phased process that is to end with the departure of all U.S. and allied combat troops by December 2014.

© Copyright The Sacramento Bee. All rights reserved.

• Read more articles by Lesley Clarkand Jonathan S. Landay

Order Reprint