The INLA statement was read out by spokesman Martin McMonagle
Gordon Brown has praised the work of the international decommissioning body as he announced three NI paramilitary groups have got rid of their weapons.
Two republican groups - the Irish National Liberation Army and the Official IRA disposed of their arms.
Mr Brown told the House of Commons the loyalist South East Antrim Ulster Defence Association had also done so.
The prime minister said decommissioning was "a central part of the process of moving NI from violence to peace".
"I think the house would want to record our thanks to the international commission which has now overseen decommissioning by the UDA, UVF, PIRA and now INLA and the Official IRA."
The legislation that enables the Independent International Commission on Decommissioning to carry out its work is due to expire on Tuesday.
At the moment, paramilitaries moving weapons can use a certificate from the IICD saying they are moving arms from one cache to another to facilitate decommissioning.
However, after the legislation expires any weapons found can be forensically tested.
Evidence from this could be used in future court cases and possibly help secure convictions.
Earlier, a spokesman for the republican terror group the INLA, Martin McMonagle, made the announcement of its weapons move at a press conference in Belfast on Monday morning.
"We make no apology for our part in the conflict," he said.
"We believe conditions have now changed in such a way that other options are open to revolutionaries to pursue and ultimately achieve our objectives."
He added: "We can also confirm that the INLA has disarmed through a joint facilitation group consisting of local, a national and an international organisation.
"This was done in a process in accordance with international standards," he said.
"We hope that this will further enhance the primacy of politics and that it will in time unite and advance the working class struggle in Ireland."
The facilitation group included Irish trade union leaders and an academic, who worked with the Independent International Commission on Decommissioning (IICD).
The trade unionists confirmed they had witnessed the destruction of a substantial amount of weaponry.
In 1993, Mr McMonagle was sentenced to 23 years in jail for his part in an INLA plot to launch a bombing campaign in England. He was released early under the Good Friday Agreement.
Irish Justice Minister Dermot Ahern said General de Chastelain had confirmed to him that over the last few days he and his colleagues had completed the decommissioning of INLA arms.
"These events are further positive developments as we look to finally close the last chapter of the conflict and ensure a peaceful future for all the people of Northern Ireland," he said.
The INLA move was also welcomed by Sinn Fein assembly member Gerry Kelly, who called for "other small militarist factions" to do the same.
"There is no support for, or appetite for, armed actions within the republican community," he said.
"The INLA has recognised this by engaging with the IICD in this action."
The INLA, whose murder victims included Tory MP Airey Neave, is believed to have disposed of its arsenal in recent weeks.
A small, ruthless group which killed more than 120 people, it announced in October that it intended to pursue its aims by exclusively peaceful means.
The republican paramilitary body is believed to have been responsible for 111 murders from its formation in 1975 until its ceasefire in 1998, but it is also thought to have been involved in a number of murders since then.
In February 2009, the INLA claimed responsibility for the murder of a drug dealer in Londonderry.
It came to world prominence in 1979 with the murder of Conservative Northern Ireland spokesman Airey Neave by leaving a bomb under his car in the House of Commons car park.
It was behind one of Northern Ireland's worst atrocities when it killed 17 people in a bomb attack on the Droppin' Well pub in Ballykelly, County Londonderry, in 1982.
The group's political wing, the Irish Republican Socialist Party held a parade in Bray, County Wicklow, four months ago where it announced that the organisation had renounced violence.
The Official IRA came into existence as a result of a split in the IRA in 1969 which also saw the emergence of the Provisional IRA.
The South East Antrim UDA split off from the mainstream organisation after its so-called brigadier was expelled in 2007.
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