BOGOTA, Colombia â€"  A Colombian official says the government delegation to peace talks with the country's main leftist rebel group in Oslo this week has not yet arrived in the Norwegian capital.

The official says the talks officially begin with a Wednesday news conference. He spoke Monday on condition of anonymity because he was not authorized to discuss the matter publicly.

The Revolutionary Armed Forces of Colombia had said the talks would begin Monday. The government never announced a date. The Bogota newspaper El Espectador said heavy rains in Colombia had delayed the arrival of FARC negotiators traveling from Havana to join their comrades for the trip to Norway.

The nearly half-century conflict has claimed tens of thousands of lives.

The talks will move to Cuba after the Oslo gathering.