MOSCOW — President Vladimir V. Putin warned on Wednesday that Russia will respond in kind if the United States decides to develop new intermediate-range nuclear missiles.

The chief of staff of Russia’s military, Gen. Valery V. Gerasimov, echoed those remarks, saying that any European countries where the United States stationed intermediate-range missiles, such as Poland or Romania, would be the first targets in the event of a conflict.

The United States has long accused Russia of developing such missiles in violation of the Intermediate-Range Nuclear Forces Treaty, which limits ground-based intermediate-range missiles. On Tuesday, Secretary of State Mike Pompeo said that the United States would within 60 days start the formal process of abandoning the treaty unless Russia re-established compliance with its terms.

In televised remarks, Mr. Putin took the familiar tack of complaining that the West was unfairly singling out Russia for what he called a “reckless decision.”