* Talks with government focus on eradicating drug crops
* Peace negotiations began in November 2012
* Progress in talks could help incumbent president in poll
By Nelson Acosta
HAVANA, May 4 (Reuters) - The Colombian government and leftist FARC rebels advanced toward a partial accord on eradicating illegal drug crops on Sunday as part of peace talks, with one rebel leader saying the mood "couldn't be better".
The two sides issued a joint statement saying they were in agreement on several points but stopped short of signing a deal. They pledged to renew talks on May 12.
Peace negotiators have been meeting in Havana since November 2012 in an attempt to reach a comprehensive agreement over a conflict that has killed more than 200,000 people over 50 years.
Any progress toward a peace agreement could provide a boost to center-right President Juan Manuel Santos, already the front-runner, as he seeks re-election on May 25.
"We are making significant progress. ... It's a good environment. I would say it couldn't be better," guerrilla leader Ivan Marquez told reporters. "At some point we will have news relating to this matter (illicit drugs)."
Government representatives declined to speak to reporters.
The two sides are working on a plan to eradicate illicit drug cultivation through crop substitution. Though Colombia imports most of the coca leaf used to produce cocaine, the South American country also grows marijuana and poppy, the raw ingredient for heroin.
But that is just one of three points on the agenda regarding drug trafficking. They will also seek a deal on prevention of drug use and a solution to the production and sale of narcotics.
The Revolutionary Armed Forces of Colombia (FARC), a Marxist-inspired armed group, has turned to drug-trafficking to finance itself.
The overall topic of narcotics is the third part of a five- point agenda the two sides have been working on for a year and a half. They have already reached accord on land use and the legal political future for the FARC should the two sides reach a comprehensive peace.
They also plan to reach agreements on compensation for war victims and the process of ending hostilities. When all five agreements are completed, they will then review the entire pact in a final round of negotiations.
Santos has bet his political legacy on ending Latin America's longest-running guerrilla war and said the FARC has little choice but to turn in its weapons.
In a Gallup poll released last week, Santos had the support of 32 percent of those surveyed versus 20.5 percent for his nearest rival, Oscar Ivan Zuluaga.
The election will go to a second round on June 15 if no candidate receives at least 50 percent of the vote. (Reporting by Nelson Acosta; Editing by Daniel Trotta and Stephen Powell)