Estonia has summoned the Russian ambassador to Tallinn over Russia's use of military power against Ukrainian sailors and vessels in the Kerch Strait.
Trump is scheduled to meet Putin at the G20 summit in Buenos Aires at the end of this week, but he told The Washington Post that it would depend on the results of a report about the incident being prepared by his national security advisers.
A Reuters journalist reported seeing a Russian warship deploying near Crimea. That fighting has killed at least 10,000 people since 2014 but eased somewhat with a 2015 truce.
Several senior European politicians raised the prospect on Tuesday and US President Donald Trump said he might cancel a meeting with Putin later this week over the maritime clash he described as "aggression".
The Ukrainian parliament on Monday voted in favour of Poroshenko's request for the introduction of martial law in border areas for 30 days. The capital of Kiev is not under martial law.
The Kremlin called the introduction of martial law a "reckless" act that "potentially could lead to the threat of an escalation of tension in the conflict region in the southeast" of Ukraine.
He spoke after Russian forces seized 3 of Kiev's ships off the coast of Crimea on Sunday, November 25, and captured 24 Ukrainian sailors. This runs counter to the claims of the Ukrainian government, which said the ships were approaching from another direction and were firmly in global waters.
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U.S. intelligence agencies have concluded that the emails were stolen by Russian intelligence officers. Sources in Ecuador tell the publication that Manafort's visit to the embassy was not logged.
Russian FSB border guards opened fire on two Ukrainian gunboats and a tug before the Ukrainian crews were seized.
The Russian president said it seemed like Kiev could get away with anything as far as foreign nations supporting Ukraine's anti-Russian stance were concerned. "If they had done something differently, they should have been put on trial for that".
While Russian forces occupied Crimea before the takeover and are heavily involved in the war in eastern Ukraine, according to Kyiv and North Atlantic Treaty Organisation, the clash in the Black Sea near Crimea was the first case in which Russia has acknowledged its military or law enforcement forces have fired on Ukrainians. Speaking to reporters as smoke billowed from a nearby shooting range, the camouflage-clad Poroshenko pledged "not to allow the enemy to attack Ukraine" and announced a hike in salaries for military members. The rest of the group was due to appear in court on Wednesday.
On Tuesday, the court ordered 15 of their compatriots to stay behind bars for the next two months. All could be sentenced to six years in prison if convicted on border-violation charges.
"Turkey would like to see brother nations Russian Federation and Ukraine side by side, not facing off, when the world is faced with serious threats", he said.
Sources in Russian security services had said in September that a fourth system would be deployed in Crimea near Dzhankoy, a town close to Ukrainian-controlled territory.