Colombia's foreign minister, Carlos Holmes Trujillo, will move to head the Defense Ministry, President Ivan Duque said on Tuesday, where he will focus on everyday security and the fight against armed groups and drug trafficking.
Trujillo will be replaced by Claudia Blum, a former senator and United Nations ambassador, Duque said.
Guillermo Botero resigned as defense minister last week in the midst of mounting political pressure over alleged extrajudicial killings and the deaths of eight children in a military bombing.
"We are pleased that Carlos Holmes Trujillo will take on this new task," Duque said in a televised statement. "He will be in charge, of course, of confronting organized armed groups in all national territory."
Trujillo's experience as mayor of the city of Cali "puts him close to the reality of citizen security," Duque added.
Trujillo, a former education and interior minister and ambassador to the European Union, has devoted much of his term as the country's top diplomat to denouncing Venezuelan President Nicolas Maduro as a dictator and supporter of terrorism.
Colombia has repeatedly accused Maduro of offering safe haven to dissidents from the Revolutionary Armed Forces of Colombia (FARC) rebel group, who refused to demobilize under a 2016 peace deal, and guerrillas from the National Liberation Army (ELN).
The fight against those groups would be easier without Maduro as Venezuela's leader, Trujillo has said.
Trujillo will also focus on fighting drug traffickers, destroying illicit cultivations of coca, the base ingredient in cocaine, and increasing drug seizures, Duque said.
Blum, a native of Cali and the first woman to serve as president of the Colombian Senate, has "ample experience in political and international affairs," Duque said on Twitter later on Tuesday.
She served as ambassador to the U.N. under former President Alvaro Uribe, Duque's mentor.