MOSCOW (AP) — The U.S. ambassador in Moscow says Russia has refused visas to teachers at a school that educates diplomats' children.

Ambassador John Huntsman says Russia hasn't issued visas to 30 new teachers who are due to arrive next month and adds "children should not be used as pawns in diplomatic disputes." He adds the school may "look at the possible disenrollment of some new and returning students" if it can't hire enough teachers.

The Anglo-American School has around 1,100 children from over 60 countries, including some children of wealthy Russians. Founded in 1949, the school is overseen by the U.S., British and Canadian embassies.

In 2016, Russian President Vladimir Putin invited U.S. diplomats' children to New Year celebrations at the Kremlin, shortly after the Foreign Ministry denied a CNN report that it planned to close the school.