Barack Obama and Raul Castro to come face to face amid bid to restore ties

As leaders from across the Western Hemisphere gather Friday in Panama, all eyes will be on two presidents: Barack Obama and Raul Castro, whose expected encounter at the Summit of the Americas will mark a historic moment as the U.S. and Cuba seek to restore ties they abandoned decades ago.
Americans and Cubans alike can recall just how deep the animosity between their countries ran during the Cold War, when even a casual, friendly exchange between their leaders would have been unthinkable. So while Obama and Castro have no formal meetings scheduled together, even a brief handshake or hallway greeting will be scrutinized for signs of whether the two nations are really poised to put their hostile pasts behind them.
Obama and Castro cross paths at the Summit of the Americas in the throes of a delicate diplomatic experiment: the renewal of formal relations between countries that haven't had any in more than 50 years.
Even their arrival Thursday evening seemed steeped in symbolism: Obama, after arriving in Panama City, was whisked via helicopter to his waiting motorcade at an airport former known as Howard Air Force Base, from which the U.S. launched its 1989 invasion of Panama.
Castro's plane landed on the tarmac minutes later, missing Obama only briefly - two world leaders passing warily in the night.
Four months ago, Obama and Castro announced their intention to restore diplomatic relations, beginning a painstaking process that has brought to the surface difficult issues that have long fed in to the U.S.-Cuban estrangement. Hopes of reopening embassies in Havana and Washington before the summit failed to materialize. The U.S. is still pushing Cuba to allow more freedom of movement for its diplomats, while Cuba wants relief from a sanctions regime that only Congress can fully lift.
Yet in the days before this year's Summit of the Americas - the first to include Cuba - both leaders sought to set a productive and optimistic tone for their highly anticipated encounter. While in Jamaica on Wednesday, Obama signaled that he will soon act to remove Cuba from the U.S. list of state sponsors of terrorism, removing a stigma that has been a source of friction for Havana.
Obama's move could come within days.
"We don't want to be imprisoned by the past," Obama said Wednesday in Kingston, Jamaica, before flying to Panama City. "When something doesn't work for 50 years, you don't just keep on doing it. You try something new."
In another sign of engagement, U.S. Secretary of State John Kerry and Cuban Foreign Minister Bruno Rodriguez met privately in Panama on Thursday - the highest-level meeting between the two governments in decades. The U.S. said the meeting was lengthy and that the leaders agreed to keep working to address unresolved issues.
On Friday, Obama was to meet with Panamanian President Juan Carlos Varela and other Central American leaders. He planned to speak at a forum of CEOs before joining other leaders for dinner at Panama Viejo, home to archaeological ruins dating to the 1500s. A visit to the Panama Canal was also possible.
In a nod to lingering U.S. concerns about human rights and political freedoms, Obama was also attend a forum bringing together both dissidents and members of the Cuban political establishment.