US President Barack Obama has arrived in Colombia for a summit of Americas nations, with Washington facing questions over Cuba's exclusion and growing dissent from regional leaders over the US-backed so-called "war on drugs".
More than 30 heads of state from the Americas are due to take part at the two-day weekend summit of the Organisation of American States' (OAS) in the Caribbean city of Cartagena.
Leaders are set to discuss important issues facing the region ranging from Cuba and drug trafficking to growing tensions between Argentina and the UK over the disputed Falkland Islands, known as Las Malvinas in Buenos Aires.
Leftist leaders from Latin America have been pushing for inclusion at the summit of Cuba, which has been excluded from the summits since its inception in 1994 at US insistence.
Ecuadorean President Rafael Correa has boycotted the summit over Cuba's exclusion, while Venezuelan President Hugo Chavez also scoffed at the meeting for not inviting Cuba due to US opposition.
Bolivian President Evo Morales said: "We have arrived with the conviction that this must be the last summit without Cuba."
Chavez, who is undergoing frequent radiation treatment in Cuba for cancer, has not confirmed if he will attend and says his doctors will decide if he can go to Cartagena.
'Forget this summit'
But he told supporters at a rally in Caracas to mark 10 years since his return to power after a failed coup that the summit was pointless unless it addressed issues relevant to Latin American nations.
"If the United States and Canada, refuse to discuss issues so profoundly unifying in Latin America like the issue of Cuba, the solidarity with Cuba or the issue of the Malvinas Islands, why else have the Summit of the Americas?" Chavez said. So we should forget this summit. As simple as that."
Another big issue on the summit agenda is drugs, with some Latin American leaders calling for a new approach to beat traffickers and reduce violence in the region.
Guatemalan President Otto Perez Molina told Al Jazeera that the "war on drugs" in the Americas was not working and that leaders must find alternatives.
The Guatemalan president has called for decriminalisation of drug consumption; a proposal Obama has rejected.
Passions are also high over the 30th anniversary of the 1982 Falklands War between Britain and Argentina.
"There should not be colonial possessions in our America," Nicolas Maduro, the Venezuelan foreign minister, said in support of Buenos Aires' demand for a negotiation of the island's sovereignty from the UK.
US influence has waned in recent years in an economically thriving region it traditionally saw as its backyard, allowing China to gain ground and emerge as the leading trade partner with various countries.
"If the United States realises its long-term strategic interests are not in Afghanistan or Pakistan, but in Latin America ... there will be great results," Colombian President Juan Manuel Santos said as he prepared to host the summit.
Latin American 'motor'
The Inter-American Development Bank, which finances various development projects, said the region contributed 14 per cent of global GDP, and looked on course to double per-capita income by 2030.
"Latin America is one of the motors of world economic recovery," the bank’s chief said.
In a reminder of Colombia's recent history of guerrilla and drug violence, four explosive devices went off late on Friday, without causing any casualties or damage to buildings, police said.
The first two explosions occurred in Bogota, the capital, before two subsequent blasts in Cartagena.
"Nobody was killed, nobody was injured, and there was no damage," a police official told AFP news agency on condition of anonymity, and without giving any word on the suspects.
Colombia is still emerging from a decades-long fight with FARC leftist rebels, who retain control of large areas of the country.
The US Secret Service, which is responsible for protecting Obama, meanwhile said it had recalled a number of agents from Colombia because of alleged misconduct but did not elaborate.
"These personnel changes will not affect the comprehensive security plan that has been prepared in advance of the president's trip," agency spokesman Edwin Donovan said in a statement.
The Washington Post newspaper reported that at least one of the agents had been involved with prostitutes in the city, quoting a US official.
Source: Al Jazeera and agencies