By NATALIYA VASILYEVA and VLADIMIR ISACHENKOV
MOSCOW (AP) — Ukraine's president on Monday urged parliament to impose martial law in the country to fight "growing aggression from Russia," after a weekend naval confrontation off the disputed Crimean Peninsula in which Russia fired on and seized three Ukrainian vessels amid renewed tensions between the neighbors.
Western leaders and diplomats urged both sides to de-escalate the conflict, and the U.S. blamed Russia for what it called "unlawful conduct" over Sunday's incident in the Black Sea.
Russia and Ukraine blamed each other in the dispute that further ratcheted up tensions ever since Moscow annexed Crimea in 2014 and threw its weight behind separatists in eastern Ukraine with clandestine support, including troops and weapons.
Ukrainian President Petro Poroshenko asked lawmakers in Kiev to institute martial law, something the country has not done even during the worst of the fighting in the east that killed about 10,000 people.
Poroshenko said martial law was necessary because of intelligence about "a highly serious threat of a ground operation against Ukraine." He did not elaborate.
"Martial law doesn't mean declaring a war," he said. "It is introduced with the sole purpose of boosting Ukraine's defense in the light of a growing aggression from Russia."
The proposed measures included a partial mobilization and strengthening the country's air defense. It also contained vaguely worded steps such as "strengthening" anti-terrorism measures and "information security."
The proposal, which could curtail certain rights and freedoms, was met with suspicion from Poroshenko's critics who wondered why Sunday's incident merited a state of emergency. Poroshenko's approval ratings have been plunging, and martial law could mean that a presidential election scheduled for March might be postponed.
Just before the parliament was to vote on the proposal, Poroshenko sought to allay those fears by releasing a statement that revised his original proposal from a 60-day period of martial law to just 30 days, in order to "do away with the pretexts for political speculation."
Oksana Syroid, a deputy speaker of parliament, noted that martial law was not introduced in 2014 or 2015 despite large-scale fighting in the east. A state of emergency "would present a wonderful chance to manipulate the presidential elections," she said.
NATO Secretary-General Jens Stoltenberg said Poroshenko assured him that should martial law be introduced, it would not have a negative impact on the election.
Poroshenko's proposal also outraged far-right groups in Ukraine that have advocated severing diplomatic ties with Russia. Hundreds of protesters from the National Corps party waved flares in the snowy streets of Kiev outside parliament and accused the president of using martial law to his own ends.
But Poroshenko insisted that it was necessary because what happened in the Kerch Strait between Crimea and the Russian mainland "was no accident," adding that "this was not the culmination of it yet."
Russian coast guard ships fired on the Ukrainian navy vessels near the strait, which separates the Black Sea from the Sea of Azov, injuring six Ukrainian seamen and eventually seizing the vessels and their crews. It was the first open military confrontation between the two neighbors since the annexation of Crimea.
Ukraine said its vessels were heading to the Sea of Azov in line with international maritime rules, while Russia charged that they had failed to obtain permission to pass through the narrow strait that is spanned by a 19-kilometer (11.8-mile) bridge that Russia completed this year.
While a 2003 treaty designates the Kerch Strait and Sea of Azov as shared territorial waters, Russia has sought to assert greater control over the passage since the annexation.
Ukrainian Foreign Minister Pavlo Klimkin tweeted that the dispute was not an accident and that Russia had engaged in "deliberately planned hostilities," while Russian Foreign Minister Sergey Lavrov blamed Kiev for what he described as a "provocation," adding that "Ukraine had undoubtedly hoped to get additional benefits from the situation, expecting the U.S. and Europe to blindly take the provocateurs' side."
Klimkin told reporters in Kiev that the government is in talks with the Red Cross to make sure the captive seamen are treated as prisoners of war. Kremlin spokesman Dmitry Peskov did not say whether the Kremlin considers them prisoners of war.
At a U.N. Security Council meeting, U.S. Ambassador Nikki Haley urged Russia to "immediately cease its unlawful conduct" in the Black Sea.
Anne Gueguen, the French deputy permanent representative at the U.N., urged the release of the sailors and the vessels.
But Russia called Ukraine's actions "dangerous." Dmitry Polyanskiy, Russia's first deputy permanent representative to the United Nations, told the Security Council the incident was another example of Ukrainian leaders trying to provoke Russia for political purposes.
The European Union and NATO called for restraint from both sides. NATO said Stoltenberg expressed the U.S.-led military alliance's "full support for Ukraine's territorial integrity and sovereignty, including its full navigational rights in its territorial waters under international law."
German Chancellor Angela Merkel also spoke by telephone with Poroshenko to express her concerns and emphasize the need for de-escalation and dialogue, her office said.
British Prime Minister Theresa May's spokesman, James Slack, said the incident was "further evidence of Russia's destabilizing behavior in the region and its ongoing violation of Ukrainian territorial integrity."
Associated Press writers Vladimir Isachenkov in Moscow, Yuras Karmanau in Minsk, Belarus, and Angela Charlton in Paris contributed.
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