Good morning and welcome to our live updates on the Ukraine crisis, where European leaders are continuing their meeting in Brussels to discuss their latest response to the crisis, as both the EU and US decide to impose further sanctions on Russian officials.
Russia is considering a "mirror response" to sanctions imposed by the West, Russia's state-run RIA news agency quotes Deputy Foreign Minister Grigory Karasin as saying.
"It should be comparable, and I will not deny that we are thinking about it."
EU leaders are also due to sign the political section of the Association Agreement with Ukraine - the accord that sparked the country's deadly unrest in November and eventually led to the ousting of former President Viktor Yanukovych by anti-government protesters angered over his refusal to sign it.
A member of the Russian navy (left) stands next to a Ukrainian soldier closing a gate bearing the Ukrainian national coat of arms on a Ukrainian naval base in Sevastopol.
Russia has tightened its grip over Crimea, with Russian-allied troops continuing to consolidate their takeover of key navy and military installations in the peninsula.
Pro-Russian soldiers took over at least two Ukrainian navy ships at anchor in the port of Sevastopol on Thursday. At least 15 men were involved in the assault, a Ukrainian defence ministry spokesman said.
Russian Foreign Minister Sergei Lavrov describes the latest sanctions as "absolutely awful," in remarks to the upper house of parliament, Reuters reports. He also said the sanctions would create artificial barriers with the West.
Pancha Chandra, Brussels, Belgium
emails: Russia has put itself in a corner with crippling, severe European sanctions. Strong-arm tactics by Putin have back-fired as European leaders hit back at Russia's unilateral action annexing the Crimea. One hopes this will not become a flash-point for deeper divisions between Russia and the West. But this whole crisis raises the very important question of Putin's consolidation of power and hegemony!
Mr Lavrov has also urged the upper house to ratify a treaty signed by President Vladimir Putin on Tuesday to make Ukraine's Crimea region part of Russia.
09:09 Breaking News
The EU and interim Ukrainian government sign Association Agreement on closer political cooperation, EU officials say