Meanwhile, Russia has moved anti-ship missiles toward the Kerch Strait and deployed an additional battery of S-400 surface-to-air missiles.

Russian President Vladimir Putin said during the weekend it is "too early" to return Ukrainian sailors and naval vessels, accusing Ukraine of provoking an incident as a distraction from domestic problems.

"The loading of grain to vessels through the ports of Mariupol and Berdyansk is restored and carried out in regular mode", it said.

Russian Federation seized three Ukrainian naval ships off the coast of Russia-annexed Crimea on Sunday (25 November) after opening fire on them and wounding several sailors, in a move that risks igniting a risky new crisis between the two countries. He said Russian Federation has stationed units on Ukrainian's eastern border that specialize in deep reconnaissance and penetration.

Last week, Russian Federation blocked the Kerch Strait, which connects the Black Sea to the Sea of Azov, effectively putting the ports of Berdyanks and Mariupol under blockade.

Russian Federation and Ukraine have blamed each other, with Moscow closing the strait to all traffic and Ukrainian officials accusing Russian Federation of denying passage to Ukrainian commercial traffic in and out of Mariupol and Berdyansk.

Last week, Omelyan accused Russian Federation of blockading cargo ships from entering or leaving the ports after a naval confrontation that involved Russian Federation seizing three Ukrainian naval ships and 24 seamen.

Stream 2 Will be Built Whether US and Baltic States Like it or Not- Prof

The seizure of Ukrainian ships on Sunday was the latest rift between the neighbors.

Poroshenko emphasized that "martial law does not mean the declaration of war", but a step toward strengthening Ukraine's defense.

But Russia, which annexed Ukraine's Crimean Peninsula in 2014, charged that the Ukrainian boats entered its territorial waters without permission.

Peskov also rejected Kiev's claim that Russian Federation was blocking traffic to and from Ukrainian ports on the Sea of Azov, saying navigation has continued normally except for occasional breaks because of bad weather. After the clash, Kiev said no Ukrainian ships were allowed through. Moscow says Ukrainian navy ships entered Russian waters while trying to cross the strait without prior notice, ignoring orders to stop. Warships have extended their presence in the Black sea from 80 day last year to 120 this year so far.

Speaking at a Ukrainian military event, President Petro Poroshenko said Russian Federation has deployed "more than 80,000 troops, 1,400 artillery and multiple rocket launch systems, 900 tanks, 2,300 armored combat vehicles, 500 aircraft and 300 helicopters" along their common border.

Poroshenko has said he tried to arrange a phone call with Putin to discuss the standoff but faced the Kremlin's refusal.