MOSCOW (AP) - Russia has signed a treaty to incorporate Crimea into its territory following a referendum in which residents of Ukraine's region overwhelmingly backed the move.
President Vladimir Putin signed the document Tuesday with Crimea's prime minister and parliament speaker following a televised address to the nation, in which he vigorously defended Crimea's vote as a restoration of historical justice.
The agreement has to be endorsed by Russia's Constitutional Court and ratified by both houses of parliament to take effect. Those steps are considered mere formalities.
Putin has accused the West of encouraging unrest in Ukraine in order to break its historic ties with Russia, and dismissed Western criticism of the Crimean vote as illegitimate.
In Poland, Vice President Joe Biden says the world has seen through Russia's actions in Crimea and will impose more sanctions on Russia.
Biden spoke Tuesday after meeting in Warsaw with Polish Prime Minister Donald Tusk. He says the U.S. joins Poland and the international community in condemning the continuing assault on Ukraine's sovereignty. He says it's a blatant violation of international law.
Biden says virtually the entire world rejects the referendum in Crimea that cleared the way for Russia to annex the peninsula in Ukraine.
British Foreign Secretary William Hague says the U.K. is suspending military cooperation with Russia in light of the crisis over Ukraine.
Speaking shortly after Russian President Vladimir Putin signed a treaty to annex Crimea from neighboring Ukraine, Hague told British lawmakers on Tuesday that it is regrettable that Putin is choosing a path of isolation in the annexation of Crimea and denying Russian and Crimean citizens of a partnership with the international community.
Hague said the U.K. is suspending military export licenses to Russia, has canceled naval exercises and suspended a proposed Royal Navy ship visit to Russia.
He said this is not the relationship Britain wants with Russia, but one it is being forced to have.
In Washington, President Barack Obama is gathering allied leaders for a meeting in Europe next week to discuss further action in response to Russia's involvement in Ukraine.
White House spokeswoman Caitlin Hayden said Obama on Tuesday invited leaders of the G-7 and European Union to meet on the sidelines of a nuclear summit next week in the Netherlands. Hayden said it will focus on what steps the group can take to respond to developments in Ukraine.
Members of the G-7 include the United States, Canada, France, Germany, Italy, Japan and Britain. The group already has suspended preparations for a G-8 Summit hosted by Russia in Sochi that has been scheduled for June.