The United States expressed regret yesterday at Syria's refusal to receive President Reagan's special Middle East envoy, Philip C. Habib, but U.S. officials insisted that they do not consider the rebuff "a final closing of the door" on efforts to achieve withdrawal of Syrian forces from Lebanon.

State Department spokesman John Hughes acknowledged that the United States wanted to send Habib to Damascus for further discussions but that Syria "has said it does not want to receive Ambassador Habib at this time."

"We believe dialogue is the best way to advance the cause of peace," Hughes said. "The Syrian attitude regarding Ambassador Habib's visit is certainly not in the spirit we hoped to have . . . . Clearly the dialogue cannot go forward for the moment if nobody is talking."

The Syrian action was especially embarrassing to the Reagan administration because Secretary of State George P. Shultz, who met with Syrian President Hafez Assad in Damascus on May 7, said that the Syrian leader had told him that he or other American representatives would be welcome to return at any time.

Shultz had planned to give Habib principal responsibility for U.S. efforts to convince Assad that withdrawal from Lebanon is in Syria's interests. Despite the belligerent tone of the Syrian snub, U.S. officials continued to say privately that they do not regard Syria as having made a definite or irrevocable decision not to cooperate with the withdrawal plan.

The U.S. position has been that Syria, despite its obvious dislike of the agreement, can be persuaded to cooperate by pressure from other Arab countries and by reminders that its continued presence in Lebanon raises the risk of renewed war with Israel.

U.S. officials that said Assad is trying to preserve his credentials as a leader of the radical, anti-Israeli forces within the Arab world and to pressure the weak Lebanese government to make concessions.