The ban will last 30 days — as long as the martial law introduced this week in much of Ukraine after Russia seized three Ukrainian naval vessels and their crews. The naval incident further escalated the tug-of-war that began in 2014 when Russia annexed Ukraine's Crimean Peninsula and supported separatist rebels in eastern Ukraine. It also has prompted global concern and renewed Western criticism of Russia, with the U.S. and its allies expressing support for Ukraine.
Yet, both sides could gain from this. By opening fire on the Ukrainian vessels, Moscow reinforced its message that Crimea is Russian for good. In Ukraine, President Petro Poroshenko is likely to benefit from the martial law he imposed. His approval ratings have been plummeting ahead of March's presidential election, and playing up the Russian threat could help him get re-elected.
In a meeting with security officials, Poroshenko said the ban targeting men between the ages of 16 and 60 should prevent Russian servicemen disguised as civilians from sneaking into the country as they did in Ukraine's east, where Moscow backed the separatist insurgency with troops and weapons in a conflict that has left more than 10,000 people dead.
Ukraine long has imposed entry restrictions on Russian men and the latest move will further tighten them, hurting bilateral trade and other exchanges across the nearly 2,300-kilometer (1,425-mile) border.
Residents of towns and villages on both sides of the frontier make regular cross-border trips to see relatives and shop at local markets, but they won't be able to do so for the duration of the ban. Cultural exchanges were also caught in cross-fire. Bolshoi Theater's soloist Andrei Merkuriev said he was denied entry to Ukraine to attend a ballet show that he staged in the southern port city of Odessa.
In Russia, officials and lawmakers reacted with dismay but said that they wouldn't retaliate to avoid hurting ordinary Ukrainians. Poroshenko's move follows Thursday's decision by U.S. President Donald Trump to scrap his much-anticipated meeting with Russian leader Vladimir Putin at the G-20 summit in Buenos Aires. Trump said it wasn't appropriate for him to meet with Putin since Russia hasn't released the Ukrainian ships and their crews.
The latest confrontation began last weekend as the three small vessels tried to pass through the narrow Kerch Strait separating Russia's mainland from Crimea. The Russian coast guard refused to let them pass from the Black Sea into the Sea of Azov, and after many tense hours of maneuvering fired on the Ukrainian boats and seized them along with 24 crewmen. Ukraine charged that its ships were in international waters, while Russia claimed the boats were violating its border.
A Crimean court ruled this week that the Ukrainian seamen will remain behind bars for two months pending Russia's investigation into the clash. Activists said they have been taken to a jail in Moscow.
Russia's Foreign Ministry spokeswoman, Maria Zakharova, claimed Friday that Moscow had demonstrated an exemplary patience, trying to prevent the Ukrainian ships from coming through for most of the weekend.
"Not a single country in the world except us would spend the entire day running after those madmen in its territorial waters, calling them, asking who they were and trying to stop them," she said. There were signs tensions wouldn't be letting up any time soon. Russian RT television on Friday broadcast footage of a convoy of massive vehicles carrying long-range Bal anti-ship missiles moving toward Kerch, near the area where the naval incident occurred.
Meanwhile, a separate fight has been brewing between Kiev and Moscow over the Orthodox Church. For centuries, the Ukrainian church has been part of the Russian Orthodox Church. Now, it's moving close to forming an independent church, a momentous step pushed by Poroshenko that would split the world's largest Orthodox denomination. The Russian Orthodox Church and Russian authorities have strongly condemned the move, warning it could trigger sectarian violence.
Ukrainian authorities have sought to portray the Russian Orthodox in Ukraine as supporting Russian-backed separatists in eastern Ukraine — claims that have been rejected by its clerics. Ukraine's domestic security agency SBU said Friday it had searched the home of Father Pavlo, who leads the ancient Pechersk Monastery in Kiev, for supposedly "inciting hatred," accusations he vehemently denied. The Pechersk Monastery, the main spiritual center of Ukraine, is under the jurisdiction of the Russian Orthodox Church.
"I'm feeling the pressure from all sides. But I would like to assure you that I am part of the holy church and I do not recognize any other church," Father Pavlo said, speaking by the ornate gilded altar at one of the monastery's cathedrals.
The search of the cleric's home came a day after Poroshenko announced that the Constantinople patriarchy had approved a decree granting the Ukrainian Orthodox Church independence from the Russian Orthodox Church, a major boost to the president's approval ratings as he runs for re-election.
Vasilyeva reported from Moscow. Vladimir Isachenkov in Moscow contributed to this report.