US Secretary of State John Kerry had urged the Colombian government and the Farc rebels to redouble their efforts to reach a peace accord.
He met both delegations in Cuba, where the negotiations are being held.
Humberto de la Calle, the head of the Colombian delegation, said the US had offered to help provide security during the disarmament process if a deal is signed.
The talks are currently centred on the sensitive issue of disarmament.
Agreement has been reached on four main areas: land reform, political participation, the illegal drug trade and transitional justice.
The two sides began formal peace talks in November 2012 in the Cuban capital, Havana.
Humberto de la Calle said Mr Kerry had offered assistance to the peace process.
“There were extraordinary concrete elements, for example, the United States’ announcement of assistance regarding the security of people who disarm, which is a critical topic in the negotiations.”
He said Mr Kerry had also offered to help in the removal of land mines, which Mr de la Calle described as “support in fiscal and monetary terms of investments that the post-conflict needs.”
Mr Kerry met the Farc delegation led by their leader Rodrigo Londono, known as Timochenko, but no details were released about the talks.
The Farc delegation gave Mr Kerry a book by the group’s founder, Manuel Marulanda Velez.
The meeting was condemned on Sunday by the former Colombian President Alvaro Uribe who said it would insult many Colombians that the US government was meeting with what he called “a cocaine trafficking cartel and terrorist group”.
US President Barack Obama has already nominated a special envoy, Bernie Aronson, to the talks and in February reaffirmed his commitment to ask the US Congress for $450m (£312m) to help with the post-conflict period after a deal is reached.