A court in Russia-annexed Crimea ordered 12 of 24 Ukrainian sailors who were apprehended at sea Sunday by Russian naval forces following a confrontation to be detained for two months.
Russia accused the sailors, who were manning three Ukrainian navy ships, of illegally entering Russian waters and ignoring warnings from Russian border guards, charges Ukraine has denied.
Ukraine has imposed martial law in some of its border regions in response to the incident, and with a growing number of other European countries, has urged Western allies to impose additional sanctions on Moscow.
President Petro Poroshenko said the martial law will help "strengthen Ukraine's defense capabilities amid increasing aggression and according to international law a cold act of aggression by the Russian Federation.
Ukraine's parliament voted Monday to approve martial law in 10 of the country's 27 regions effective Wednesday.
The measure calls for 30 days of martial law, an apparent concession to opponents, which would allow for the country’s presidential elections to be to be held as scheduled, on March 31 of next year.
Russia fired on two Ukrainian naval ships and rammed a third vessel Sunday in the Black Sea, seizing the ships and accusing them of illegally entering its territorial waters.
U.N. Secretary General Antonio Guterres urged Ukraine and Russia Tuesday to exercise “maximum restraint” to avoid further escalation in the region.
The North Atlantic Council, the main decision-making body of NATO, said "there is no justification for Russia's use of military force against Ukraine" and called on Russia to release the sailors "without delay."
U.S. Ambassador to the United Nations Nikki Haley condemned Russia for its "outrageous violation of sovereign Ukrainian territory."
"This is no way for a law-abiding civilized nation to act," Haley said at a Monday emergency meeting of the U.N. Security Council. "Impeding Ukraine's lawful transit through the Kerch Strait is a violation under international law. It is an arrogant act that the international community must condemn and will never accept."
When asked at a White House media briefing Tuesday whether U.S. President Donald Trump would condemn acts of Russian aggression against Ukraine, National Security Advisor John Bolton replied "we'll stand on" Haley's comments at the U.N.
At the U.N. Security Council, most members condemned the escalation, urged restraint and called for the unconditional and immediate release of the Ukrainian sailors and the return of their ships.
Poroshenko is demanding Russia immediately release the Ukrainian sailors and ships.
At the U.N. Security Council, most members condemned the escalation, urged restraint and called for the unconditional and immediate release of the Ukrainian sailors and the return of their ships.
Poroshenko is demanding Russia immediately release the Ukrainian sailors and ships.
NATO chief Jens Stoltenberg also called on Russia to release the Ukrainian navy ships, saying "there is no justification" for Moscow's actions, while European Union chief Donald Tusk condemned Russia's use of force and reiterated the EU would stand in support of Ukraine.
Reacting to Kyiv’s imposition of martial law, Russian President Vladimir Putin warned Ukraine in a phone call with German Chancellor Angela Merkel Tuesday against committing any “reckless acts,” saying he was “seriously concerned” about the developments.
Russia's deputy envoy to the U.N., Dmitry Polyanskiy, blamed Kyiv and its Western supporters for the escalation.
"This provocation was pre-planned, that's obvious, and it was with the full connivance of Western states that de facto have just given carte blanche to any actions taken by their subordinates," he said at an emergency session of the U.N. Security Council Monday.
Ukraine's U.N. ambassador, Volodymyr Yelchenko, said his government would like to see a tightening of economic sanctions on Moscow.
"The sanctions is the only real tool that can make Russia at least start thinking of their behavior," Yelchenko said after the meeting. "Sanctions, they do bite."
"We think our sailors committed no crime whatsoever," Yelchenko said, noting that Crimea is not recognized as Russian territory by anyone except Russia. "What are they claiming, that Ukrainian sailors committed a crime by crossing the Russian border? Where is this border? It does not exist."
Sunday's incident began when a Ukrainian tugboat set out to escort two navy ships from Odessa, on the Black Sea, through the Kerch Strait to the Ukrainian port of Mariupol, in the Sea of Azov.
The Kerch Strait is the only passage between the two seas.
Ukraine said Russia used a tanker to block access to the Kerch Strait, which under a treaty is shared territory.
The Trump administration has previously warned Russia against trying to strangle Ukraine’s economy by harassing international shipping through the Kerch Strait.
Russia annexed Ukraine's Crimean Peninsula in March 2014, claiming its ethnic Russian majority was under threat from the Ukrainian government. A month later it fomented a pro-Russia separatist rebellion in eastern Ukraine in an ongoing conflict that to date has claimed more than 10,000 lives.
Ukraine and the West repeatedly have accused Russia of fueling the conflict by providing rebel forces with weapons and other support, a charge Moscow has been denying despite strong evidence to the contrary.
VOA's Fern Robinson and Wayne Lee contributed to this story.
