The United States and Panama pledged yesterday to make "a sustained and continous effort" to reach early agreement on a new Panama Canal treaty, and scheduled the resumption of negotiations for Feb. 10.

Secretary of State Cyrus R. Vance and Panamanian Foreign Minister Aquilino Boyd made the pledge in a joint statement after a meeting at the State Department. The meeting followed National Security Council deliberations - the first of the Carter administration - recommending maximum U.S. efforts to reach final agreement on a new canal treaty by this summer.

With Boyd at his side, Vance told reporters that the main questions to be resolved are the termination date of the new treaty - the time when the United States will give up its rights under the 1903 agreement - and the questions of access to, and defense of, the canal after the new treaty runs out.

Panama is demanding that the U.S. Physical presence and all U.S. treaty rights terminate by the end of the century. The United States, on the other hand, is seeking guarantees of open access to the canal that would continue into the 21st century. How to accomodate the two viewpoints in a formula that would preserve principles and save face all around is the heart of the negotiation.

President Carter said during the campaign and repeated Sunday that he would not relinquih "practical control" of the canal. He did not define "practical control" but said he is hopeful about a new treaty.

A National Security Council Policy review committee headed by Vance has reviewed the existinhg U.S. positions, forged a plan for negotiations an agreement and recommended a time-table.

The Defense Department participated in the activity, but it is not known whether the Pentagon has taken a new "bottom line" position on its requirements for an acceptable agreement.

Expecting resistance from conservative political forces in and out of Congress, the Carter administration is anxious to make a new treaty and finish Senate ratification before the canal can become an emotional issue in 1978 political jockeying. Vance recently told members of Congress that it should be possible to complete a new treaty by June, and there are some suggestions that a conclusion could come even earlier.

Carter has said he is contemplating a "fireside chat" to explain to the country why new canal arrangements are necessary. Senior lawmakers have told him the treaty could become bitterly embattled in Congress - to the detriment of the U.S. position in Latina America and the Third World - if not skillfully handled.

Speaking to reporters briefly in the State Department lobby, Boyd said that Panama plans to take control of the canal after the year 2000 and will defend the canal after that time. He said Panama is willing to accept responsibility for "primary defense" of the waterway even earlier.