WASHINGTON (CNN) -- President Bush will seek to persuade reluctant European allies to commit more troops for the fight in Afghanistan at his last North Atlantic Treaty Organization summit this week.
More than six years after the United States retaliated against Taliban targets in Afghanistan after the September 11, 2001, attacks, a resurgence of the ousted regime has led to heavy fighting in southern Afghanistan.
The president left early Monday for the summit in Bucharest, Romania, and aides said he plans to keep up pressure on NATO allies. 
Watch Bush's comments before his departure »
"We all need to do more," national security adviser Stephen Hadley said at a briefing with reporters last week. "I think the president's message is going to be one of the importance of success in /topics/afghanistan_war" class="cnnInlineTopic">Afghanistan."
But Julianne Smith, a senior fellow at the Center for Strategic and International Studies in Washington, said more /topics/nato" class="cnnInlineTopic">NATO troops alone will not address Afghanistan's deeper challenges.
"Even if NATO succeeds in securing say 2,000 to 3,000 more troops ... we are still facing a situation where without the required reconstruction assistance, NATO will not be able to succeed," Smith said. Watch the twin battles that British forces are fighting in Afghanistan »
Also on /topics/george_w_bush" class="cnnInlineTopic">Bush's agenda: laying the political groundwork for a missile defense system in Eastern Europe as well as enlarging NATO to include the eventual membership of former Soviet republics Ukraine and Georgia.
Both moves have infuriated Moscow, which views the issues as potential challenges to Russia's influence in the region.
Nevertheless, Bush plans to start his trip with a visit to Kiev, the capital of Ukraine, ahead of the summit.
Yet in a sign of the importance of the U.S.-Russian relationship, Bush will end his overseas visit by accepting an invitation from outgoing Russian President Vladimir Putin to meet at the Black Sea port city of Sochi, Russia.
Putin is first expected to attend the NATO summit to argue against Ukraine's and Georgia's membership bids. How confrontational Putin is in voicing his opposition may set the tone for the meeting in Russia with Bush, who has less than 10 months left in his term.
"What President Bush is trying to do on this visit is as he leaves office, try and patch up the relationship with Russia as best he can before the next U.S. president gets into office," Smith said. E-mail to a friend 
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