Russian President Vladimir Putin said Sunday that the U.S. diplomatic missions in Moscow and elsewhere in the country will have to reduce their staffs by 755 people, signaling a significant escalation in the Russian response to American sanctions over the Kremlin’s intervention in the 2016 presidential election.

The United States and Russia have expelled dozens of each other’s diplomats before — but Sunday’s statement, made by Putin in an interview with the Rossiya-1 television channel, indicated the single largest forced reduction in embassy staff, comparable only to the closing of the American diplomatic presence in the months following the Communist revolution in 1917.

In the interview, Putin said that the number of American diplomatic and technical personnel will be capped at 455 — equivalent to the number of their Russian counterparts working in the United States. Currently, close to 1,200 employees work at the United States’ embassy and consulates in Russia, according to U.S. and Russian data.

“More than a thousand employees — diplomats and technical employees — have worked and are still working in Russia these days,” Putin told journalist Vladimir Solovyov on a nationally televised news show Sunday evening. “Some 755 of them will have to terminate their activity.”

Putin’s remarks came during a 3½ -day trip by Vice President Pence to Eastern Europe to show U.S. support for countries that have chafed at interference from Moscow — Estonia, Georgia and Montenegro.