Today: President Reagan acts as host for morning and afternoon meetings with Soviet leader Mikhail Gorbachev at the Chateau Fleur d'Eau

The two leaders meet privately for 15 minutes at the outset.

Then, in the morning meeting, the two will discuss U.S.-Soviet relations. The president will be accompanied by Secretary of State George P. Shultz, White House chief of staff Donald T. Regan, national security affairs adviser Robert C. McFarlane, U.S. Ambassador to Moscow Arthur Hartman, Assistant Secretary of State Rozanne L. Ridgway and Jack F. Matlock Jr., a Soviet specialist on the National Security Council.

Reagan will present "the current position of the U.S., how we see our interest internationally, how we perceive Soviet policies and actions and, finally, how we think the two sides should get along with each other," according to presidential spokesman Larry Speakes. The session is to conclude at 12:15 p.m.

Reagan then will have a working lunch with senior U.S. officials. At 2:30, Reagan and Gorbachev meet again at the chateau to discuss arms control. In this session, Ambassador Paul H. Nitze, special adviser to Reagan and Shultz on arms control, will take the seat that Ridgway had in the morning meeting.

The afternoon meeting is to conclude at 4:35 p.m., and Reagan will escort Gorbachev to his motorcade.

At 8 p.m., the president and Nancy Reagan are to attend a dinner hosted by the Gorbachevs at the Soviet United Nations mission. Reagan is to be accompanied by Shultz, Regan, McFarlane and Hartman. The dinner is to end at 10 p.m. Wednesday: Gorbachev is to act as host for a morning and afternoon meeting with Reagan at the Soviet mission.

The first meeting, on regional conflicts, is to begin at 10 a.m. Reagan then will go to the Maison de Saussure for a working lunch with U.S. officials. He then will return to the Soviet mission for talks on bilateral and human-rights issues. The meeting is to conclude at 4:30 p.m. The president will be accompanied by the advisers who were with him Tuesday morning.

At 7 p.m., the Reagans are to arrive at the Chateau La Gandole, where they will be met by Kurt Furgler, president of Switzerland, and his wife. The Reagans and the Gorbachevs will be guests of the Swiss for a reception.

At 7:45 p.m., the Reagans are to return to Maison de Saussure, and at 8:15 greet the Gorbachevs for a dinner that is to end at 10:15 p.m. Thursday: Reagan and Gorbachev plan a joint appearance to sign cultural and air-safety agreements and to review the summit. Details are being worked out.

Reagan's departure from Cointrin Airport is planned for 1:45 p.m., with a brief stop in Brussels to brief NATO allies. Upon his return to Washington Thursday night, Reagan is to go to the Capitol to deliver a nationally televised address before a joint session of Congress shortly after 9 p.m