Update

From reports, it seems the offensive by Ukrainian forces against pro-Russian separatists who took over the Donetsk airport earlier today was successful. 

After fighting that lasted into a rainy evening, the military appeared to have evicted the separatists from the airport, cordoning off the area with roadblocks. The airport remained closed."

If true, this is a huge boon for Ukrainian President Poroshenko, who just 24 hours ago was declaring victory in the Ukraine's first elections since the ouster of former pro-Russian President Viktor Yanukovych just three months ago. 

Original Post

Pro-Russian forces wasted no time in seizing a major airport in eastern Ukraine just hours after billionaire candy tycoon Petro Poroshenko was elected president.

Poroshenko immediately ordered a major offensive to take the airport back.

Monday's rapid military response to separatists who seized the airport in Donetsk appeared to be a defiant answer to Moscow, which said it was ready for dialogue with Poroshenko but demanded he scale back the armed forces' campaign in the east."

Poroshenko gave a particularly muscular acceptance speech after he was declared the new president yesterday, declaring that he would root out "terrorist" forces in eastern Ukraine and bring Ukraine closer to the European Union.

Meanwhile, Russia signaled that it would respect the outcome of Ukraine's elections and that it was ready to talk. Tell that to the separatists who have declared Donetsk—Ukraine's fifth-largest city—to be an independent republic. Here they are on the roof of the airport.

As Ukrainian troops fight to wrest control of the airport back from the rebels, Poroshenko has been delivered the first major test of his presidency.