"By decommissioning their weapons they not only demonstrate their commitment to building a peaceful future in Northern Ireland but also their confidence in the political situation and the security of the union," the DUP leader said.
"As leader of the largest unionist party, I want to encourage those who were previously engaged in paramilitarism to focus their energies fully on transforming the social and economic situation in their communities.
"Under Direct Rule many of these loyalist working-class areas were neglected. I am certainly committed to working with those communities to build a more prosperous and peaceful future for their next generation."
Sinn Fein also welcomed the announcements.
"Obviously people will still be slightly sceptical. They will wait for General John de Chastelain to verify that. So we look forward to that", Gerry Kelly said.
"But it is a move forward. It is taking more guns off the street."
"It proves that politics is working, that there is an alternative way forward and we're eager to move the whole process, embed the institutions to move the political process forward."
'Historic day'
Earlier this year Secretary of State Shaun Woodward set a deadline of August for decommissioning to start, threatening to close down the decommissioning avenue if loyalists did not start to put their weapons beyond use.
On Saturday he welcomed the UVF/RHC announcement and he encouraged the UDA to complete the decommissioning process with the IICD.
"This is an historic day for people in Northern Ireland," said Mr Woodward.
"The leadership of the UVF and RHC have today taken a bold and courageous decision for peace.
"For those who have doubted the political process it is proof that the politics works, and that guns have no place in a normal society.
"I have always kept faith with the peace and political process of which the decommissioning legislation has played a crucial part this is proof that decommissioning works and today's acts of leadership is further testimony to the transformation in Northern Ireland."
He added: "When parliament renewed the decommissioning legislation for the final time in February I believed it was possible to achieve the decommissioning of these weapons."
'Peace'
President of Ireland Mary McAleese who has been involved in efforts to reach out to loyalist communities, also welcomed the decommissioning statements.
The President said: "This is a very important step in building and consolidating peace in Northern Ireland and signals a turning away from a culture of conflict towards a culture of good neighbourliness, within Northern Ireland and on the island of Ireland.
"In order to build on this important and welcome progress, we encourage those who have not yet completed the process to do so in co-operation with the IICD."
Alliance party leader David Ford said the developments were good news for Northern Ireland.
He said: "Communities who have suffered at the hands of these groups will be reassured that it appears that they have decommissioned fully.
"We now need to see the UDA doing the same as quickly possible. They cannot stall any further and must meet the decommissioning deadline set down by the Secretary of State."
'Painful memories'
Catholic Primate Cardinal Sean Brady also welcomed the news.
"My first thoughts are for those for whom this news will evoke painful memories of loved ones lost and lives destroyed through the utter futility and evil of violence," he said.
"News of these acts of decommissioning will be particularly welcomed within the Catholic community which was the target of so much of the violence of Loyalist paramilitary groups.
"I pray that what has been announced today will help us to move further away from fear and suspicion to greater trust, goodwill and friendship among all, whatever our background or identity."
SDLP leader Mark Durkan said it was important they were sensitive to the mixed feelings of the victims of loyalist violence and all other victims who have suffered so much throughout the years.
"The paramilitaries must stop all their illegal activities and end their malign inference in their communities without delay," he added.
'Mindset'
UUP leader Sir Reg Empey said failure by loyalists to deal with the weapons issue was always going to be used by some republicans as an excuse to maintain their paramilitary capability.
"These latest and long overdue statements represent one more chapter in the long road to peace and democratic practice in Northern Ireland.
"We look forward to further action from the UDA, followed by a change in the mindset in loyalist areas, which, along with deprived nationalist areas, have not benefited from the peace process to the extent that we would like."