BOGOTA, Aug 11 (Reuters) - Colombia is unlikely to sign a peace accord with Marxist rebels this year as the remaining items on the negotiating agenda are complex and time consuming, FARC guerrilla leader Rodrigo Londono said.
President Juan Manuel Santos had expressed hope that talks to end a half century of war with the Revolutionary Armed Forces of Colombia (FARC) could be concluded as soon as this year though he acknowledged they could run on longer.
In an interview published on the rebels' website on Monday, Londono said there would not be time in the next four months to complete discussion on reparation to victims and how to bring a definitive end to the conflict.
"I'm afraid not. Of course we all want things to be concluded as soon as possible," said Londono, known by his nom de guerre of Timochenko.
"It is easy to see that the timeframe of this year won't allow for it. It should be noted also that the subject of the surrender of arms and a bilateral ceasefire will not be simple."
Dozens of FARC and government negotiators have reached agreement in talks - taking place in Cuba - on land reform, how to end Colombia's illegal drugs trade and rebel participation in politics.
In an apparent response to Santos' recent warnings that talks could collapse if the FARC continue to attack civilian and economic targets, Londono insinuated that the killing of any member of its seven-member secretariat would disrupt talks.
"We have no intention of assimilating the death of another member of the Secretariat, unless it be by natural causes," he said.
Santos, sworn into office for a second term last week, has been responsible for killing several FARC leaders, including Londono's predecessor, Alfonso Cano.
Even as the group has been weakened by a decade-long U.S.-backed military offensive, a rash of attacks against oil and mining installations, as well as on the armed forces and civilians, prove it is still a force to be reckoned with.
Santos, 63, warned at his inauguration last week that Colombia's patience for the peace talks has limits.
"Our intention is not to leave the negotiating table until there is a final agreement. But we do not believe that allows our adversaries to pull the rope so tight," Londono said in an apparent response.
The center-right Santos pounded FARC militarily before revealing at the end of 2012 that the two sides would seek to end a conflict that has killed more than 200,000 people.
The FARC, which has battled a dozen governments since it began in 1964, took up arms as a Marxist group struggling against inequality. It later turned to kidnapping and drug-trafficking to finance itself. Colombia is a leading producer of cocaine. (Reporting by Helen Murphy; editing by Andrew Hay)