Soviet Foreign Minister Eduard Shevardnadze on Saturday said the Kremlin would consider a rearmament step or a break with the intermediate-range nuclear arms treaty if NATO upgrades its short-range nuclear missiles.

The veiled threat to match a NATO proposal to increase the range of European-based Lance rockets was the latest Soviet effort to pressure the West into a new round of arms talks.Shevardnadze met with West German Foreign Minister Hans-Dietrich Genscher for four hours Saturday. The talks focused on the contentious missile issue, which has divided NATO.

The United States wants NATO approval this month on a plan to modernize, or more than triple, the range of the Lance rockets by 1995. But West Germany has balked and is pressing for superpower talks on reducing short-range weapons.

Most of NATO's short-range missiles are based in Germany, and public opinion here is strongly against the modernization step for fear it would jeopardize arms control efforts.

Shevardnadze said the modernization project was tantamount to development of a new weapons system, and he said the Kremlin would not want to have to take a similar step.

"This would have to be considered, but it would not be by our own choice," Shevardnadze warned at a news conference before returning to Moscow.

He likened the new missiles NATO plans to develop to the Soviet SS-23s being dismantled under the December 1987 superpower accord eliminating medium-range missiles.

"Why should we liquidate the SS-23 if the other side is creating and will deploy an analogous Lance-2 rocket?" the foreign minister said. "It makes no sense to destroy these rockets then."

He said destruction of the SS-23 would have to be halted "or we would have to create a new system." Suspension of the SS-23 liquidation would violate the INF treaty.

NATO plans to replace the Lance missiles, which have a range of less than 75 miles, with missiles capable of reaching up to 300 miles. That would keep them within the limits allowed under the 1987 accord.

The United States has repeatedly said it wants a balance of conventional arms in Europe before entering into talks aimed at elimination of short-range missiles.

Genscher has long advocated a more trusting relationship between the superpowers.