Mr. Bush, speaking at the State Department, and his advisers sought to portray the cease-fire deal as an affirmation of American foreign policy.
It made headway, though a separate Russian team reached a cease-fire deal before Mr. Volsky's group.
A cease-fire deal was signed last month by six African governments involved in the fighting, though the main rebel group has yet to sign.
In a statement they said the restrictions violated the Vienna Convention on diplomatic relations and the cease-fire deal approved by Russia and Georgia.
He called it a clear violation of repeated cease-fire deals, the most recent of which was signed on Nov. 9 in Abuja, the Nigerian capital.
The latest cease-fire deal, announced Friday morning, has brought at least a temporary reprieve.
He declined to say if he would attend, but said it was pointless to discuss constitutional and electoral reform, the main topics, without working on a cease-fire deal.
The war just bumps along for 5 or 10 years and everybody eventually gets so weary that diplomacy finally gets going, and there's a cease-fire, power-sharing deal.
Contra leaders last week accepted that reality and worked out a 60-day cease-fire deal with Managua.
Lebanese army posts were shelled and gunfire was heard late on May 27, despite a cease-fire deal at Nahr al-Bared.