MOSCOW — President Vladimir V. Putin on Friday suspended all flights from Russia to Egypt, the most popular foreign tourist destination for Russians, until the cause of a mysterious plane crash that killed 224 people over the Sinai Peninsula can be established.

Mr. Putin’s decision was the first breach in what has largely been a consistent response from Russian and Egyptian authorities to the crash on Saturday. Until now, the two countries have been playing down the possibility of terrorism — even as Prime Minister David Cameron of Britain said it was likely a bomb and President Obama said “we are taking that very seriously.”

A Kremlin spokesman said that Mr. Putin’s decision did not mean that the crash was caused by a terrorist act. Mr. Putin ordered that measures be taken to ensure that the roughly 45,000 Russian tourists already in Egypt could be brought home safely.

Samples from the wreckage from the crash site in the Sinai Peninsula have been taken to Moscow for examination.