Dr Williams said relations between the churches would not be damaged
Groups of Anglicans will be able to join the Roman Catholic Church but maintain a distinct religious identity under changes announced by the Pope.
The Vatican said the new rules follow requests from Anglicans wanting to join but retain their liturgical heritage.
It comes amid splits among Anglicans worldwide over homosexuality and the ordination of women.
But Archbishop of Canterbury Dr Rowan Williams said he did not think it was a "commentary on Anglican problems".
Causes of discord in the worldwide Anglican communion have included the election of an openly gay bishop and the blessing of same-sex unions.
In the Church of England, the ordination of women as priests, and the prospect of their appointment as bishops, has led many Anglicans to consider joining the Roman Catholics.
Two senior opponents of women bishops said they would announce their reaction to the Vatican move in February.
The measure, known as an Apostolic Constitution, was shown to leaders of the Church of England just two weeks ago.
Under its terms announced by the Vatican, groupings of Anglicans would be able to join "personal ordinariates".
This would allow them to enter full communion with the Catholic church, but also preserve elements of the Anglican traditions including the possible use of Anglican prayer books.
Speaking at a Vatican press conference, Cardinal William Levada, prefect of the Congregation for the Doctrine of the Faith, said the constitution was a response to "many requests" from groups of Anglican clergy and worshippers wanting to enter into full communion with the church.
Cardinal Levada said it "provides a reasonable and even necessary response to a worldwide phenomenon".
End of 'uncertainty'
One group of Anglicans which has requested a formal structure to be corporately received into the Catholic church has been the Traditional Anglican Communion, according to the Vatican.
This group is made up of an estimated 400,000 members worldwide.
Speaking at a news conference held jointly with the Most Rev Vincent Nichols, leader of Roman Catholics in England and Wales, Dr Williams rejected the idea that the new arrangement would damage relations between the two churches.
He said: "I do not think this constitution will be seen as in any sense a commentary on Anglican problems offered by the Vatican.
The Vatican has had ongoing discussions with the Anglican church
"It is a response to this range of requests and inquiries from a very broad variety of people, either Anglican or of Anglican heritage, in that sense it has no negative impact on the relations of the communion as a whole to the Roman Catholic church as a whole."
In a statement issued by Lambeth Palace, the archbishop said the move "brings to an end a period of uncertainty for such groups who have nurtured hopes of new ways of embracing unity with the Catholic Church".
He said the Apostolic Constitution "is further recognition of the substantial overlap in faith, doctrine and spirituality between the Catholic Church and the Anglican tradition".
The archbishop's statement went on: "Without the dialogues of the past 40 years, this recognition would not have been possible.
"With God's grace and prayer we are determined that our ongoing mutual commitment and consultation on these and other matters should continue to be strengthened."
An Anglican bishop who said he was prepared to convert to Roman Catholicism after the General Synod voted to allow women bishops, said he warmly welcomed the Vatican announcement.
The Right Reverend Andrew Burnham, Bishop of Ebbsfleet, said in a statement on his website: "Now is not a time for sudden decision or general public discussion."
He and colleague Keith Newton, Bishop of Richborough, said in a joint statement, "We have chosen 22nd February... to be an appropriate day for priests and people to make an initial decision as to whether they wish to respond positively to and explore further the initiative of the Apostolic Constitution."
Bishops Burnham and Newton are "flying bishops" - appointed following the decision of the Anglican Church to ordain women priests to minister to those parishes which opposed the move.
In their statement they said: "Following the decision of General Synod of the Church of England in July 2008 to proceed with the ordination of women to the episcopate, we appealed to the Holy Father for help and have patiently awaited a reply.
"This Apostolic Constitution, addressed worldwide, feels to us to be a reply to concerns raised by others and by us and an attempt to allow all those who seek unity with the Holy See to be gathered in without loss of their distinctive patrimony."