Russia annexes Crimea

Russia has formally annexed Crimea, taking over the peninsula from Ukraine in a move condemned by Western governments as a breach of international law.

The Russian president, Vladimir Putin, signed a treaty with the leaders of Crimea in Moscow on 18 March, two days after a referendum in which the region voted to join Russia.

The referendum

Crimea's local authorities say almost 97 per cent of voters backed joining Russia in the referendum on 16 March. Western governments and Ukraine say the vote was illegal and was held under the pressure of Russian troops, who took control of the peninsula in late February.

Many Crimean Tatars and ethnic Ukrainians boycotted the vote.

Putin's speech

In a speech to the Russian parliament, Putin said Crimea had always been an inseparable part of Russia, and accused the West of hypocrisy. He said Russia had to protect Russian-speaking people in Crimea.

Crimea, which has a majority ethnic Russian population, was transferred from Russia to Ukraine in 1954, when both were part of the Soviet Union. Russia's Black Sea Fleet is based in the Crimean port of Sevastopol.

Crisis in Ukraine

The crisis began after Ukraine's pro-Russian president, Viktor Yanukovych, was forced out of office last month, following months of protests in Kiev sparked by his decision to reject closer ties with the European Union.

Russia says the new government in Kiev is illegitimate.

Sanctions

The United States and the European Union have imposed sanctions, including travel bans and asset freezes, on Russian and Crimean officials. They have warned of tougher measures if Russia moves further into Ukraine.

The Prime Minister, David Cameron, said Russia's actions were completely unacceptable and that there must be consequences.

G8

Western leaders are discussing whether to suspend Russia from the G8 group of leading industrial nations, and a summit due to be held in Sochi this summer is in doubt.

Fears

There are fears that Russia could move into eastern Ukraine, where there are also many Russian speakers. Russia has large numbers of troops near the border.

Ukraine's government has said it will never accept the loss of Crimea.