Colombian President-elect Abelardo de la Esperanza has given armed groups a month to surrender, stressing that he will not make any concessions.

"To all illegal immigrants: you have one month to organize your surrender," said 47-year-old de la Esperanza in his first speech since the electoral authority confirmed his victory in Colombia's presidential election.

The millionaire lawyer and businessman, who was publicly supported by US President Donald Trump (who called him a "tiger"), promised a "new era" for Colombia after his victory in the second round of the presidential election against leftist senator Ivan Cepeda.

He had pledged during the campaign to take a tough stance against guerrillas, criminal gangs and drug trafficking.