Colombia's FARC rebels have formally completed a disarmament process to end half a century of war against the state, the United Nations said.

UN monitors "today stored away the entirety of the FARC's registered individual arms," except for some that were exempted for transitional security at demobilisation camps, the UN said in a statement.

The move carried out by Colombia's biggest rebel group under a 2016 peace accord brings Latin America's oldest civil conflict close to a complete end.

Former tánaiste Eamon Gilmore, who is in Colombia as EU Special Envoy, attended the disarmament ceremony on behalf of the EU's High Representative for Foreign Affairs and Security Policy, Federica Mogherini. 

He also welcomed the release of a Colombian human rights defender who was sentenced to 18 years in prison.

Mr Gilmore said that the release of David Rabelo, who he visited in prison in 2015, was a "significant part of the country's ongoing process."