The fighting rages in eastern Ukraine ahead of the agreed 15 February ceasefire deadline, which comes into effect at midnight (22:00 GMT).
An agreement aimed at ending the conflict in eastern Ukraine has been found, following four-way talks between the leaders of Ukraine, Russia, Germany and France.
The US is examining the option of supplying “lethal defensive weapons” to Ukraine if a peace deal is not reached to end the crisis in the east of the country, Barack Obama has said.
European and US leaders are pushing for a new peace deal in eastern Ukraine, as fighting escalates between the Ukrainian military and Russian-backed separatists.
Ukraine and pro-Russian rebels they have been fighting for five months in the east have agreed to a truce deal.