Pre-Summit Talks to Seek a Nuclear Pact Draft : Weapons: Soviets arrive in Washington for final preparatory session. Both sides hope to restart stalled negotiations on conventional forces. : The Washington Summit. Dealing with the New Reality

Soviet negotiators arrived in the United States on Saturday for a final pre-summit round of arms talks, seeking to eliminate the last obstacles to a draft nuclear weapons agreement and to restart stalled talks on conventional armed forces in Europe.

The head of the Soviet delegation, arms control expert Viktor P. Karpov, told reporters that President Mikhail S. Gorbachev plans to seek limits on the military power of a reunified Germany when he meets with President Bush beginning Thursday.

“We need some guarantees that this new Germany will respect European security and that the armed forces of the new state will be under some control,” he said.

U.S. officials said they are optimistic that the two sides can work through the remaining issues in the nuclear strategic arms reduction talks (START) when they begin meeting today. Bush and Gorbachev are scheduled to approve its terms in a declaration this week.

“We’re just about there,” said a senior Administration official, noting that the remaining problems in the proposed START accord are “not major policy issues.”

On conventional arms, U.S. officials said they hope for a positive Soviet response to several compromise proposals made by Secretary of State James A. Baker III in Moscow two weeks ago.

The talks on Conventional Forces in Europe (CFE) have been at an impasse for months while Moscow reconsidered its security posture after the collapse of Eastern Europe’s Communist regimes. The negotiations are intended to produce a treaty under which the North Atlantic Treaty Organization and the Warsaw Pact would make deep cuts in troops, aircraft, armored vehicles and artillery.

In Moscow, Baker took the Soviets a package of U.S. “ideas” intended to explore Soviet flexibility and re-energize the negotiations, but he received no concrete response.

Officials said the U.S. suggestions covered most of the issues on which NATO and the Soviets are at odds in the talks: limits on aircraft and armored forces, destruction of weapons that are withdrawn, manpower ceilings for each alliance and verification procedures.

One major issue stems in part from Soviet worries that a reunified Germany might become a major military power again. The Kremlin has proposed a troop ceiling of about 750,000 on each alliance, a provision that would have the effect of constraining German troop levels.

Previously, the United States had argued that no such limits were necessary. But in his recent Moscow meetings, Baker hinted at a new, more flexible U.S. position, according to one official. He said Baker told the Soviets that NATO would attempt to “accommodate Soviet concerns about German force levels in the current (CFE) negotiations or later.”

In START negotiations, half a dozen “second-order” issues remain to be resolved:

* Warheads on mobile land-based missiles. The United States has backed off its longstanding proposal to ban all land-based mobile multiple-warhead missiles, so now both sides are trying to set a limit on the warheads carried by mobile launchers.

* Limits on the Soviet Union’s modernization of its heavy SS-18 missile. The United States had proposed banning production and flight tests of these weapons. The Soviets already have agreed to halve their SS-18 force from 308 to 154; but during the eight-year course of the START negotiations, they have also developed an improved version, called Mod 5. The new U.S. proposal is to limit flight testing and end production of the Mod 5, but Moscow has shown no interest in that.

* The Soviets’ Backfire bomber. Moscow refuses to include these under the START limits because it says they are medium-range aircraft, not long-range. The United States wants them included but may drop the issue.

* Perimeter and portal monitoring. The two sides disagree on the kinds and numbers of nuclear weapon facilities where on-site inspectors from each side would police operations.

* Non-circumvention. START bans both countries from giving the weapons limited by the pact to other countries, but the United States wants to maintain a longstanding program to help Britain develop sea-based nuclear forces. The Soviets are expected to agree.

* “Follow-on” negotiations. At the summit, Bush and Gorbachev are expected to issue a joint statement promising to follow the START treaty with START-2 talks. But the two sides haven’t agreed on what should be included in the next negotiations. The United States wants to reduce the Soviet arsenal of SS-18s and ballistic missiles with multiple warheads; the Soviets want more limits on air- and sea-launched cruise missiles. Arms control experts predict the statement will be vague, leaving the question of the START-2 agenda to be worked out later.