The decision left officials on both sides of the Atlantic scrambling to find out how long the pause might last.

The White House cited Pentagon concerns that some American arms stockpiles were dwindling too low. Among the affected weapons were air defense systems, bombs, missiles and artillery rounds.

By lifting sanctions against Syria, US President Donald Trump removed some Russian companies, banks, and individuals from under certain restrictions. However, they were removed only from the so-called Syrian sanctions regime,