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.
The move stoked already high tensions between Moscow and Kiev, as Russia continues to accuse the sailors of crossing illegally into Russian waters and of ignoring warnings from its border guards.
"It is completely obvious that if Ukraine, either by itself or with the help of its allies, somehow tries to resolve issues by military means, this will all turn into a military defeat".
President Poroshenko said martial law will help "strengthen Ukraine's defense capabilities amid increasing aggression and according to worldwide law, a cold act of aggression by the Russian Federation".
Trump said the decision would depend on his reading of a full report on the situation he was due to receive late Tuesday, adding, "I don't like that aggression". They had been traveling from the Ukrainian port of Odessa, on the Black Sea, to the Ukrainian port of Mariupol on the Sea of Azov.
According to him, the incident was a provocation by the Ukrainian authorities and, possibly, the country's president, Petro Poroshenko, on the eve of the presidential elections.
President Putin has lashed at Ukraine over its imposition of martial law, depicting it as a cynical pre-election ploy by the country's unpopular president while also mocking western countries over their "short-sighted" support for Kiev.
Western leaders and diplomats urged both sides to deescalate the conflict, and the USA blamed Russian Federation for what it called "unlawful conduct" over Sunday's incident in the Black Sea.
Ukraine also accused Russian warships of opening fire on the ships, asserting that crew members were wounded and the vessels were seized by Russia. Ukraine insists they are prisoners of war, says some were seriously injured in the confrontation and has asked the International Red Cross to arrange a visit to see them.
"It shouldn't happen, it shouldn't happen", Trump said.
Captured Ukrainian navy sailors are conveyed to Kiev district court of Simferopol, Crimea. Twenty-four sailors were detained and "courts" in Russian-occupied Crimea ruled that they be detained for two months, pending trial. "This can be the best guarantee for the security of this area from Russian aggression", says Parubiy.
The strait links the Black Sea with the Sea of Azov and is where Russia has built a long new bridge _ the only land link between Crimea and the Russian mainland.
"Russia wants to consolidate its illegal annexation of Crimea and annex the Sea of Azov... and seems to hope that the global community will simply acquiesce and accept this new reality".
Meanwhile, U.S. State Department spokeswoman Heather Nauert urged European states to do more to support Ukraine and said Washington wants to see tougher enforcement of sanctions against Russian Federation.