President Barack Obama is in his home town of Chicago, Illinois, where he will host leaders of the 28 trans-atlantic allies for the NATO summit beginning Sunday.
Obama arrived in Chicago after discussions with leaders of the Group of 8 major developed economies in Camp David, Maryland.
That G8 summit covered the Eurozone debt crisis, the Arab Spring and Syria, energy security and oil prices, food security, and Afghanistan, the key focus of the NATO summit.
NATO leaders, along with partner countries, will discuss and decide on the level of financial support for Afghanistan's military after 2014, when foreign troops are to formally end their combat role.
In a statement to media before leaving Camp David, President Obama looked ahead to the decisions NATO needs to make: "Tomorrow we begin our NATO summit in my home town of Chicago, where we will discuss our plans to responsible end the war in Afghanistan," he said.
Obama's first meeting Sunday morning will be with Afghanistan President Hamid Karzai.
NATO plans call for about $4 billion in annual support to sustain Afghanistan's military. By next year, Afghan forces are to assume the full security lead in all areas of the country.
However, there are concerns about levels of support, with NATO members facing budget tightening. France's President Francois Hollande has reaffirmed his plan to withdraw 3,300 French troops by the end of this year, saying France supports Afghanistan in other ways.
The president of Pakistan, Asif Ali Zardari, is also here. Pakistan decided last week to re-open supply lines in its territory crucial to the movement of NATO supplies into Afghanistan.
With heads of state and government of some 60 countries here, along with officials and leaders of international organizations, security in Chicago is the tightest seen in decades.
Authorities established a cordon, or protective area, around the huge convention center where the NATO summit is taking place. Journalists covering the summit are bused from hotels 15 minutes away.
Though there have been demonstrations over the past week about NATO military policies and a variety of other issues, the largest protest is expected on Sunday as the leaders of NATO countries and partner nations begin their discussions.
Chicago police said three men arrested in a raid on an apartment last week planned to attack President Obama's campaign headquarters, the home of Mayor Rahm Emanuel, police stations, and other targets.
The three were formally charged with conspiracy to commit terrorism and possession of explosives. But attorneys for the men said they were victims of entrapment by Chicago undercover police.