Ukrainian President Petro Poroshenko has announced on Friday through social media platforms that the country would restrict the entry of Russian males aged 16-60.
"These are measures to block the Russian Federation to form detachments of private armies here, which in fact are representatives of the Armed Forces of the Russian Federation," Poroshenko said.
"And not allow them to carry out the operations that they tried to conduct in 2014," he added.
The move came after Poroshenko declared martial law in several Ukrainian regions near the Russian border after Russia fired on and captured three Ukrainian naval ships off Crimea last weekend.
The president also said in a statement on Facebook that Ukraine has received 500 million euros (568 million dollars) in assistance from the European Commission.
The EU, the U.S., and the International Monetary Fund have supported Ukraine's economy since 2014.
Poroshenko said the disbursal of 500 million euros was a "very important signal of the unwavering assistance of the European Union against the recent challenges from Russia".
Ukrainian President Petro Poroshenko chairs a meeting with heads of military and security forces in Kiev, November 30, 2018. /VCG Photo
Hungary chose to back Ukraine, said Prime Minister Viktor Orban during a visit to Prague on Friday.
"Hungary's stance is clear-cut, we are a pro-Ukraine government, so we stand behind Ukraine," Orban said in response to a reporter's question.
"There is a pro-Ukraine government in Hungary, while there is an anti-Hungary government in Ukraine. Despite that, we have not changed our stance and we will stand behind Ukraine in this conflict."
Russia: No plans to ban entry to Ukrainian men
Russia does not plan to ban Ukrainian men from entering the country in a tit-for-tat response, RIA news agency cited a Russian lawmaker as saying on Friday.
Ukraine and Russia have blamed each other for last Sunday's clash at the Kerch Strait through which ships have to pass to reach Ukrainian ports at Berdyansk and Mariupol.
It prompted Ukraine to introduce martial law for a period of 30 days from Wednesday in regions of the country thought most vulnerable to a Russian attack. Poroshenko has requested NATO to deploy ships to the area.
EU to extend sanctions on Russia
The European Union will extend its existing economic sanctions on Russia next month, European Council President Donald Tusk said on Friday.
"Europe is united in its support to Ukraine's sovereignty and territorial integrity. This is why I am sure that the EU will roll over the sanctions against Russia in December," Tusk told a news conference in Argentina, where the leaders of the world's 20 biggest economies were meeting.
The bloc first imposed measures against Russia's defense, energy and banking sectors in 2014.
(With inputs from Reuters)