Petro Poroshenko will update US and EU leaders on discussions with Russia's President Vladimir Putin. 

 

France has ramped up the pressure on Mr Putin by suspending delivery of two navy assault ships to Russia.

 

Some 2,600 people have been killed in five months of fighting between Ukraine's army and rebels in the east of the country.

 

The West says it has evidence that President Putin is supporting the rebels with training and arms, but Russia denies this. 

 

The conflict has forced more than a million people from their homes in eastern Ukraine, according to latest United Nations estimates.

 

The two-day Nato summit in Newport is expected to be dominated by the crisis in Ukraine, but leaders will also discuss the rise of Islamic State (IS), and Afghanistan.

 

Writing in the Times, UK Prime Minister David Cameron and US President Barack Obama said they would "confront" IS, warning that people who wanted an "isolationist approach" misunderstood the situation.

 

"Developments in other parts of the world, particularly in Iraq and Syria, threaten our security at home," they said.

 

"Countries like Britain and America will not be cowed by barbaric killers."

 

Their statement comes following the release of a new IS video showing the killing of US journalist Steven Sotloff, just days after the group beheaded another American reporter, James Foley.

 

In the latest video, an IS militant is also seen threatening to kill a UK hostage.