The Soviet Union is continuing to insist to British and French officials that their nuclear forces be counted in western totals at the Geneva talks on medium-range nuclear missiles and has also repeated that position to the United States, NATO sources said today.

NATO officials exchanged reports on their most recent contacts with the Soviets at a meeting here today of the Special Consultative Group, which meets regularly to discuss the Geneva talks. Afterward, Assistant Secretary of State Richard Burt, who chairs the group, said in a statement that the "Soviet Union continues to pursue a course which creates obstacles to an agreement."

The possibility that the Soviets may be modifying their stance on British and French weapons was raised in Madrid on Friday by West German Foreign Minister Hans-Dietrich Genscher, who said the hint had come in a meeting he had with Soviet Foreign Minister Andrei Gromyko.

As Genscher explained it, Gromyko had said that the British and French arsenals had a "dual face," suggesting that they could be considered both strategic as well as medium-range weapons. Such flexibility would help break the logjam at the medium-range talks by making it possible for them to again focus strictly on the relative strengths of the United States and the Soviet Union.

Moscow had been maintaining that all allied forces should be included in measuring the nuclear balance with the Soviets in Europe. That view has been rejected by the United States and by the British and French, who contend that their national nuclear forces serve only strategic purposes. Genscher said he found Gromyko's statement "remarkable in a positive sense."

However, in meetings in Paris Friday with French officials, including President Francois Mitterrand, and earlier with Secretary of State George P. Shultz and British Foreign Secretary Sir Geoffrey Howe in Madrid, Gromyko offered no indication that the Soviet position was beginning to shift on the issue.

While there is no doubt here that Genscher accurately reported his meeting with Gromyko, the fact that the Soviet foreign minister did not mention a similar concession on the missiles in talks with other allied officials tends to downgrade its significance, sources said.

Nonetheless, officials say the key test remains Moscow's attitude in the actual negotiations at Geneva, and on that score no changes are evident.

According to Burt, the Soviets have yet to explain the meaning of President Yuri Andropov's recent offer to destroy some of their SS20 missiles as part of a bargain with the West. Burt said the Russian definition of "liquidate" did not specify the extent of dismantling that would be involved and whether new missiles would be produced to replace those that are eliminated.

"Provisions to ensure that destroyed SS20s are not simply replaced with new missiles must be included in any agreement," he said.

NATO sources said modifications in the American position at the medium-range talks are now under active consideration in Washington and will probably be presented next week after they are approved by President Reagan. The sources declined to discuss the nature of those changes.

Burt merely said that the American stance is subject to an "ongoing review."

Today's meeting reaffirmed the NATO intention to go ahead with deployment of Pershing II and cruise missiles in Western Europe beginning later this year if negotiations are not successful. In response to a question, Burt said that the Pershings are now regarded as technically ready for deployment, having successfully completed 13 of 17 tests.