It was a vote of 444 against one as Russia's lower house of parliament on Thursday approved a treaty to annex Crimea from Ukraine.
The upper house is expected to complete ratification on Friday and President Vladimir Putin and Crimean leaders will ink it early next week.
"This decision to accept Crimea into the Russian Federation complies with the international law, including the principle of sovereign equality written in the UN Charter and the right to self-determination."
As Russian forces take over more Ukrainian military bases in Crimea, Ukraine is speeding up its withdrawal of soldiers.
In parts of Crimea, residents are lining up to apply for new passports.
"We are in Russia. We are Russian citizens now, what do we need Ukrainian passports for? We will exchange them with great pleasure."
"It won't be worse, it will be better. It says a lot that the young are in support of Crimea joining Russia, and all of us here have voted unanimously at the referendum."
UN Secretary-General Ban Ki-moon met with President Putin Thursday in Moscow, urging for a peaceful settlement to the crisis.
The UN chief travels to Kiev on Friday to deliver the same message.
"They should really resolve this issue peacefully. But first and foremost, most important way is to for Russia and Ukraine sit down together and engage in direct and constructive dialogue."
This come as U.S. President Barack Obama expanded sanctions to take in a Russian bank and some high-profile Russian billionaires with close ties to Putin.
Russia also announced travel bans against nine prominent Americans, including senators Harry Reid and John McCain.
Hwang Sung-hee, Arirang News.
And, the European Union has also slapped travel bans and asset freezes on 12 more people bringing the number of Russians and Ukrainians facing EU sanctions to 33.
The 28-nation bloc said the names of the sanctioned would be published Friday.