Iran considered attacking a seaport in Ukraine in response to a Ukrainian strike on an Iranian ship, but a flurry of diplomacy has calmed the situation for now, according to Iranian and Western officials, The New York Times reported Tuesday.

Ukraine, which has accused Iran and Russia of supporting each other’s military operations, struck an Iranian commercial cargo ship in the Caspian Sea on Saturday, killing a civilian sailor. Iranian officials vowed to retaliate.

Some people briefed on the intelligence said that they expected Iran to fire a ballistic missile with a small warhead at Ukraine, to make a symbolic point but cause relatively little damage. Other officials said the target was probably one of Ukraine’s Black Sea ports.