Nuclear talks between Iran and six world powers could continue right up to Tuesday’s deadline, U.S. officials said Sunday, as the two sides sought to hammer out the outlines of a final deal. The officials pointed to several unresolved issues in the negotiations, including the phasing of suspension and then lifting of United Nations Security Council sanctions on Iran, and the activities Tehran will be able to engage in during the final years of an agreement, which is now expected to last 15 years. 

China's top political advisor Yu Zhengsheng wrapped up his visit to Vietnam here on Saturday, during which he agreed with the Vietnamese leaders to enhance mutual trust and properly settle maritime disputes through negotiations.

After failing to reach their own deadline for a comprehensive nuclear agreement, the world’s major powers and Iran settled for an extended truce that avoids the hard political choices that neither Washington nor Tehran could make.

USC international relations expert studies the art and practice of negotiations.

Colombian police reported that 292 cases of kidnapping were registered in 2013, of which 32 could be directly traced to the FARC, despite the rebel group's promise to cease the practice -- a government precondition for peace talks. In February 2012, the rebels of the Revolutionary Armed Forces of Colombia (FARC) announced they would cease the practice of “retentions” (the guerrilla word for kidnapping), which was a government precondition for sitting down and negotiating an end to the 50-year civil conflict.

Negotiations with Marxist guerrillas are closer than ever to ending a 50-year conflict, Colombian President Juan Manuel Santos said in an interview after a breakthrough in talks, even as his political opponents accuse his government of selling out to the rebels. “I think this time we will reach an agreement, and we will have peace,” Santos said, appearing relaxed, the collar of his dress shirt unbuttoned, as he flew on the presidential plane to this northern city to oversee infrastructure projects. “We have never even been close to what we have already achieved.”

For a little under a year, the Colombian government and the Revolutionary Armed Forces of Colombia (FARC) have been holding peace talks in Havana -- the first since the round conducted by the Pastrana administration from 1998 to 2002. Those were plagued by delays, accusations from the FARC that the Colombian government was planning to assassinate its top leaders, accusations from the Colombian government that the FARC was planning to kidnap officials, and ongoing violence.