Colombia’s President Juan Manuel Santos has said he will ask President Obama to help implement a peace accord that his government expects to sign with the Farc rebel group next month.
The two presidents will meet at the White House on Thursday.
“Part of the conversation with President Obama is how can they help us in the post-conflict,” he told the BBC.
The Farc says it is willing to lay down its weapons after more than five decades of conflict.
Peace negotiations were launched in Cuba in November 2012.
The Colombian government and the left-wing rebels have set a 23 March deadline to reach an agreement.
The post-conflict period “is more difficult than the process itself”, said Mr Santos.
White House officials told Reuters news agency earlier that Mr Obama was willing to increase aid to Colombia to secure the success of the accord.
The Farc, which was founded in 1964, will give up its armed struggle and join the legal political process.
Last week, the United Nations Security Council voted to accept a request from the Farc and the Colombian government to appoint a mission to oversee the end of the conflict.
“This is really a step that makes the process irreversible,” said Mr Santos.
He added the rebels also agreed to “cut every link that they have with drug trafficking”, as part of the accord.
“They recognise that they have financed themselves through drug trafficking, or taxing the drug traffickers. That’s what they say.
“And they will in a way help us, especially in those remote areas, to convince the peasants to switch to legal crops,” he told the BBC.
Colombia is the world’s top producer of cocaine.
Mr Santos and Mr Obama are also expected to discuss ways of combating the spread of the Zika virus.
Colombia is the second most affected country by the current outbreak, after Brazil. It has more than 20,000 reported cases.
“We in a way are expecting a rapid increase. We expect this to go, reach a plateau and come down,” he said.
“The problem with Zika is nobody knows a lot about what it is.”