Colombia's Senate has approved a revised peace accord with the country's largest rebel group, the Farc.

The Revolutionary Armed Forces of Colombia (FARC) announced Tuesday that its members will not start heading for the areas where they must gather before laying down their arms due to the lack of infrastructure in those areas and "legal obstructions."

Colombia's Congress has ratified a revised version of the peace accord with the FARC, a positive sign of political will to move the process forward despite lingering uncertainties concerning the time frame for implementation.

Thousands of Colombians have taken part in marches to demand that a peace deal signed by the government and Farc rebels be upheld.

The Colombian president on Wednesday said that his country would soon have a new peace agreement which would facilitate closer trade ties with the United Kingdom.