MOSCOW — Russia’s Foreign Ministry has recently denied visas for teachers at a school in Moscow run by Western embassies, in what American officials suggested was an effort to exert political pressure on the United States by curtailing schooling for the children of diplomats.

It is not clear why the Russian government denied entry to 30 teachers, about one fifth of the teaching staff at the Anglo-American School of Moscow; the Foreign Ministry did not respond to written questions on Tuesday. But Moscow’s conflicts with Washington and London have flared repeatedly in recent years, and the school has been in the political cross hairs before.

After the Obama administration imposed sanctions on Russia in late 2016 for interfering in the United States election, an American official told CNN that the school could be closed in retaliation.

President Vladimir V. Putin, however, delayed a response after Michael T. Flynn, on his way to becoming the national security adviser to President Trump, told the Russian ambassador in Washington that the Trump administration would have a different policy toward Russia.