Ukraine’s military said its two-day missile drill starting on Thursday would avoid the airspace over Crimea, sidestepping a possible confrontation with Russia which annexed the peninsula in 2014.

News of the tests had angered the Kremlin, prompting it to put its air defense forces on high alert and maneuver warships in the Black Sea.

The disagreement marked a fresh escalation in tensions between the neighbors and one-time allies, whose relations collapsed after Russia seized Crimea and backed pro-Russian separatists fighting in eastern Ukraine.

Volodymyr Kryzhanovsky, a Ukrainian military official, said the exercises, which are taking place in Ukraine’s southern Kherson region bordering Crimea, were being carried out in accordance with international law.

The exercises were taking place at least 30 km (18 miles) from Crimea’s air space, “therefore it would be wrong to reproach Ukraine,” he told the 112 TV channel.

Moscow initially responded to the test plans by putting its land-based and ship-borne air defense forces in Crimea on higher alert and a Russian military source accused Ukraine of trying to create a “nervous situation.”

On Thursday Russia’s federal aviation agency, Rosaviatsia, said in a statement that it had received new coordinates for the tests that meant the “danger zone reserved for missile launches does not now affect the air space over Russian territorial waters.”

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