Juan Manuel Santos, sworn in as Colombia's 59th president, vowed to cement security gains but declared himself open to dialogue with rebels in hopes of ending the Western Hemisphere's only armed conflict.
He also got to work immediately mending frayed relations with neighbouring Venezuela and Ecuador. Although he was invited, the Venezuelan President Hugo Chavez was not among the 14 Latin American and Caribbean leaders, including Felipe Calderon, of Mexico, and Luiz Inacio Lula da Silva, of Brazil, at Saturday's ceremony on Bogota's central plaza. Also absent was Mr Chavez's close ally, President Evo Morales of Bolivia.
Mr Chavez broke diplomatic ties with Colombia two weeks ago after the outgoing hard-line president Alvaro Uribe's government presented the Organisation of American States with video of alleged Colombian rebel camps in Venezuela.
Mr Chavez did, however, send his foreign minister.
In Caracas later, after he heard Mr Santos express a desire for improved relations, Mr Chavez said he was ready "to turn the page and look to a future with the hope of peace, brotherhood and full integration between Colombia and Venezuela".
President Rafael Correa, of Ecuador, did attend the inauguration, though he severed ties with Mr Uribe's government in 2008 after the Colombian military raided a guerrilla camp a mile inside his country, killing a rebel chief and 25 others.