BONN, West Germany (AP) _ A jubilant Chancellor Helmut Kohl said Tuesday that all major obstacles to German unification had been swept aside and said elections for a united German parliament were likely in December.

Speaking to reporters the day after he returned from the Soviet Union with guarantees that a united Germany was free to join NATO, Kohl also said he hoped bilateral treaties with the Soviet Union and Poland could be concluded by early next summer.

''The practical problems, which lay before us on the way to German unity, have been solved,'' Kohl said.

He said elections for a united German parliament on Dec. 2 were ''presumable.'' But whether East Germany merged with the West before or after the elections had to be decided by East Berlin, he added.

The deputy chairman of the largest faction in the East German Parliament said East Germany could vote to join West Germany under its constitution on Dec. 1.

Udo Kamm of the Christian Democratic coalition said his faction would vote for such a proposal in a committee Thursday. The proposal would then go to the full Parliament.

In Washington, President Bush said Soviet President Mikhail S. Gorbachev's consent for a united Germany in NATO was ''very, very significant and very important.'' Bush said the United States deserves a lot of credit.

''I take pride in the way Europe is moving into this new era of freedom,'' he said. ''It's a goal that we Americans have long worked to achieve.''

In a 40-minute telephone call to Gorbachev, Bush assured him that NATO poses no threat to the Soviet Union and that the United States is ready to move toward warmer relations, officials said.

Kohl also tried Tuesday to reassure Germany's neighbors.

''We are no world power,'' he said, emphasizing that the new Germany would be embedded in the ''European security architecture.''

He said he was sensitive to the concerns of fellow Europeans. He noted that Britain had gambled ''its very existence'' in battling Hitler. He said it was no accident Germany had agreed to reduce the size of a united army to 370,000 and cut compulsory military service from 15 to 12 months.

East German Foreign Minister Markus Meckel, however, rejected the idea of one German army and said East Germany needed its own military. Currently, the two Germanys have about 600,000 men under arms, 480,000 of them in West Germany.

In Paris, meanwhile, the nations negotiating German unification reached a historic agreement, confirming Poland's border with East Germany and clearing the way for one Germany by year's end.

West Germany also agreed to hold economic assistance talks with Poland later in the summer.

Terms of the border settlement were not announced. Polish Foreign Minister Krysztof Skubiszewski said they were confidential, but all the foreign ministers stressed the border would be the line between Poland and East Germany that was drawn at the end of the war.

''We are very happy with the results,'' Skubiszewski said. ''The border has been confirmed.''

The border settlement should serve to allay Polish concerns that a merged Germany would revive old claims on territory given to Poland in partial compensation for a larger area taken over by the Soviet Union.

In evaluating the role of the new Germany in central Europe, Kohl said he envisioned it as a ''transit point for ideas and perspectives'' between West and East.

The treaty with the Soviets, Kohl said, could include economic aid. But he said no specific financial aid was offered during his weekend visit to induce the Soviets to remove one of their biggest obstacles to German unification - objections to a united Germany in the North Atlantic Treaty Organization.

Foreign Minister Hans-Dietrich Genscher, who accompanied Kohl and Finance Minister Theo Waigel on the trip to Moscow, also said West Gemany and the Soviet Union reached agreement on cooperation without West Germany giving specific aid promises.

''We reached agreement ... on long-term cooperation, but we have not discussed any numbers,'' Genscher said in Paris.

Waigel said the Soviets presented ''no bill'' for their acceptance of German reunification. But he said it was in the German interest for the Soviet reform process to succeed.

West Germany has already backed a $3 billion bank credit to help the Soviet Union revamp its economy and has agreed to pay $780 million toward the upkeep of Soviet soldiers stationed in East Germany in the second half of this year.

At last week's Houston summit of Western industrial powers, Kohl had pushed for a $15 billion international aid package for the Soviet Union. Instead, the leaders asked the International Monetary Fund to study what kind of aid would be most beneficial.

Kohl ruled out the possibility that West Germany would be the sole future source of financial aid to the Soviets, saying the burden would be too great.

However, he said he could envision West Germany helping the Soviets retrain thousands of soldiers returning from East Germany, who could face unemployment back home.

It was also possible, he said, for West Germany to help in supplying housing but ''not for a certain category of Soviet residents.'' West German officials are concerned about the domestic political fallout of building housing specifically for returning Soviet troops.