Foreign Minister Tariq Aziz of Iraq Monday accused Iran of stalling peace talks by rejecting the immediate reopening of the Shatt-al-Arab waterway, Iraq's only outlet to the sea.

The disputed waterway has been blocked by sunken ships since the outbreak of the 8-year-old Persian Gulf war.Iranian Foreign Minister Ali Akbar Velayati rejected Iraq's claim to the entire waterway. He told reporters Sunday night that the 1975 treaty had been accepted by both sides and could not be abrogated unilaterally by Iraq.

The peace talks resumed Monday at a downgraded, technical level because both countries' foreign ministers removed themselves after a snag developed late Sunday over Iraqi demands for full sovereignty over the Shatt-al-Arab.

U.N. Secretary-General Perez de Cuellar met for six hours Sunday night with the separate delegations and acknowleged the talks had run into difficulties over the withdrawal of troops behind internationally recognized borders.

In reply to a question, the U.N. leader said: "We cannot say now that we have reached deadlock. The possibility always exists."

With negotiations on the verge of a deadlock, Aziz said at a morning news conference, "We have not found any measure of good faith from the other side" since the peace talks started last week.

"I hope we will move back to the ministerial level as soon as the disagreement is settled," Perez de Cuellar said.

"The negotiations are continuing without underrating the difficulties that we face at the moment," added U.N. spokesman Francois Giuliani.

Aziz said the immediate clearing of the Shatt-al-Arab would allow Iraq to regain use of its only outlet to the sea.