Ukraine's interim leadership pledged to put the country back on course for European integration now that Moscow-backed Viktor Yanukovich has been ousted from the presidency, while the United States warned Russia against sending in its forces, Reuters reports.

As rival neighbors east and west of the former Soviet republic said a power vacuum in Kyiv must not lead to the country breaking apart, acting President Oleksander Turchinov said late on Sunday, Feb 23, that Ukraine's new leaders wanted relations with Russia on a "new, equal and good-neighborly footing that recognizes and takes into account Ukraine's European choice".

European Union foreign policy chief Catherine Ashton will travel to Ukraine on Monday, where she is expected to discuss measures to shore up the ailing economy.

Russia said late on Sunday it had recalled its ambassador in Ukraine for consultations on the "deteriorating situation" in Kyiv.

EU officials offered financial aid to a new government and to revive a trade deal that Yanukovich spurned in November, sparking the protests that drove him from office after 82 deaths last week.

In addition to any economic assistance the EU might offer, the United States has also promised help. Budgets are tight on both sides of the Atlantic, and international creditors may be wary of Yanukovich's opponents, whose previous spell in government was no economic success.

Turchinov said a government should be in place by Tuesday.

His ally, Tymoshenko, defeated by Yanukovich in a 2010 presidential election and later jailed for corruption, ruled herself out as interim premier. Freed from a prison hospital on Saturday after more than two years in jail, she may want time to recover and build support before running for the presidency.