A day after the US said troops will soon be on the way to Saudi Arabia in response to last week’s drone attacks on two major oil facilities, Iran said it would conduct a joint naval drill with China and Russia “soon.”

The announcement came as the war of words between Saudi Arabia and Iran also heated up.

“Be careful, a limited aggression will not remain limited. We will pursue any aggressor,” the head of the Iranian Revolutionary Guards, Major Gen. Hossein Salami, said in remarks broadcast on state TV following the US announcement that troops will soon be on their way to Saudi Arabia.

Saudi Foreign Affairs Minister Adel al-Jubeir said that the kingdom is “certain” that the drone launch did not come from Yemen, as Houthi rebels there claimed.

“It came from the north,” he said, implying it came from Iran. “It was done with Iranian weapons, therefore we hold Iran accountable for this attack. The kingdom will take the appropriate measures based on the results of the investigation, to ensure its security and stability.”

While Iran’s news agency announced a naval drill with Russia and China will take place in the Sea of Oman and northern Indian Ocean — but not the Persian Gulf — neither country appeared to confirm the plans immediately.

China and Iran held joint exercises in the Persian Gulf two years ago. If Russia joins the announced exercises, it would be the first time the three nations worked together.