US hopes to keep Camp David peace process alight . . . with verbal diplomatic fuel supplied by Mr. Haig

As the April deadline for Israel's pullout from Egyptian Sinai nears, the two nations are busy haggling over the future status of the territory.

The next round of negotiations is expected to be tenser than any of the previous ones, since it will deal with the sensitive issue of the future demilitarized zone; an area to be patrolled by a multinational peacekeeping force, and under the surveillance of early warning stations.

The main focus of the talks will be on:

Rafah. A subcommittee will meet at the end of this month after exploring this Mediteranean coast town cut by the international border. Rafah is inhabited by 40,000 Egyptians and Palestinians. The Egyptian families will have to be moved to the Egyptian sector of the town. The subcommittee will decide on where the border checkpoint cutting the town will be built and on rules governing the movement of residents from one sector to the other.

Settlements. Egypt has reluctantly agreed to let the Israeli government dismantle some installations in the nine settlements of the northern sector after the April 25 withdrawal date. Compensation for the settlers will be estimated after an Egyptian committee visits the settlements prior to the handover.

International border. The joint military committee will convene soon to determine 16 disputed border points. The major points of disagreement are where to place the border checkpoint west of the Israeli port of Eilat and where to place a border demarcation mark in the Taba Valley.

Tiran and Sanafir. Egypt has assured Israel it will raise the Egyptian flag on the barren yet strategic islands of Tiran and Sanafir, and station an Egyptian police force at the latter island overlooking the Aqaba Strait leading to Israel's only port on the Red Sea. But the Israelis want peacekeeping forces to patrol the islands claimed by Saudi Arabia. Discussions with the head of the peacekeeping force will decide the matter.

Part of the problem in planning the future status of the Sinai is that the Israelis regard the area as a front line, which should be only sparsely populated if at all. The more towns and cities in the region, they argue, the less comfortable Israel will feel about its border, since these populated areas could serve as a refuge for Palestinian troublemakers.

Israeli Defense Minister Ariel Sharon, who led the delegation to the most recent round of formal talks which ended Jan. 19, suggested that Israel retain control over Rafah and underlined the need for guarantees that Egypt would not acquiesce to Saudi pressure to regain control over Tiran and Sanafir.

The Egyptians reacted coolly to the Israeli proposals. They said the Israeli propositions ''went too far'' and emphasized a diametrically opposed view toward the future of the area. ''Israel cannot dictate its views on the fate of a previously occupied area,'' said one official, adding that plans have already been worked out to exploit the agricultural and tourist potential of the area to help relieve the mainland's cities from overpopulation. When developed, the area will ''stand as a human barrier to war, and the best assurance of a lasting peace,'' the Egyptian official said.

In preparation for the pullout Egypt recently bought from Israel $16.2 million worth of tourist installations, power stations, and equipment and facilities at the airport of Ras Nusrani and the port of Sharm el Sheikh.

A group of tourism and aviation specialists who visited the area last month to evaluate what the Israelis offered to leave behind reported that the two main airports of Ras Nusrani and Ras en Naqb were not in operating condition, and that converting them from military airbases to civilian airports would be very expensive. (The Israeli government stopped development and maintenance operations in Sinai after it signed the peace treaty three years ago.)

Egyptian negotiators in the coming talks have received clear directives not to give in to any Israeli pressure and not to give up ''one inch of land,'' according to one official.

The acceleration of the talks on withdrawal will coincide with US Secretary of State Alexander M. Haig's renewed interest in the Middle East. Mr. Haig will visited Israel Jan. 27 and travels to Cairo Jan. 28 for further talks on Palestinian autonomy. It is his second such trip this month.