Ukraine readies for possible Russian invasion

Ukrainian soldiers are laying seige to Donetsk, where pro-Russian rebels have taken control.

After heavy fighting, much of the town remains in ruins.

But the soldiers are also preparing for a larger battle. They believe Russia is preparing to invade.

NATO is warning that Russia could use the pretext of a humanitarian mission to send in the 20,000 combat-ready troops now positioned on Ukraine's border.

Ukrainian Defence Council spokesman Andriy Lysenko says the military will be ready to respond:

(SOUNDBITE) (Ukrainian) UKRAINIAN NATIONAL SECURITY AND DEFENCE COUNCIL SPOKESPERSON, ANDRIY LYSENKO, SAYING:

"If there is direct aggression, then it is obvious that there will be an adequate answer from all branches of Ukrainian armed forces."

The battle between Ukraine government troops and separatist rebels has been raging since April.

Economic sanctions from the west, and threats of further action against Russia, have had little affect.

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