Right-winger Duque gave the Marxist ELN a one-month deadline after his inauguration on August 7 to convince him it is serious about laying down arms and reentering civilian life.

That cut-off point expired on Friday.

By refusing to recognize agreements reached under Duque's predecessor, Juan Manuel Santos, "and unilaterally placing unacceptable conditions, this government is... ending the process of dialogue" aimed at reaching a peace agreement, ELN negotiators in Havana said in a statement.

The statement called for restarting talks "with no further delays."

Duque on Saturday demanded the release of all ELN hostages -- believed to be 16 -- as a condition to restart peace talks.

With an estimated 1,500 fighters, the ELN is the last recognized armed rebel group operating in Colombia. Authorities believe it is financed through drug trafficking and illegal mining.

Santos won the Nobel Peace Prize for signing the historic accord with the much larger Revolutionary Armed Forces of Colombia (FARC) rebels in 2016, turning that armed group into a political party after more than 50 years of violent insurrection.