Yanukovych calls Biden on dramatic day

Ukraine's President Viktor Yanukovych called Vice President Joe Biden in their second conversation in as many days as his country's political showdown reaches a pivotal point.

The call took place after Ukraine's prime minister and entire government resigned and parliament scrapped anti-protest laws in the biggest concessions yet to opposition protesters.

The new contact between the White House and Kiev also came on a day when Russian President Vladimir Putin warned foreign nations against interfering in the politics of ex-Soviet states.

The White House said that Biden welcomed "progress made today" in Ukraine and called on Yanukovych to sign the repeal of several anti-protest laws passed on January 16 laws without delay.

"He strongly encouraged President Yanukovych to continue to work with the opposition to find compromises critical to a peaceful solution," it announced, in a statement.

"These include an amnesty law and a new government that can bring political unity, win the confidence of the Ukrainian people, and take Ukraine in the direction of Europe by strengthening democratic institutions and making the reforms necessary to achieve economic prosperity."