US President Barack Obama can "go to hell" over his criticism of the Philippines brutal war against drugs, President Rodrigo Duterte says.

The European Union - another critic - "better choose purgatory, hell is filled up", Mr Duterte said.

The remarks came as the US and the Philippines began joint military exercises. The US said there was a "strong alliance" with the Philippines.

Mr Duterte's drugs war has caused thousands of extrajudicial killings.

In a speech to local officials and business executives Mr Duterte said he was disappointed with the US for criticising the Philippines' tactics to combat the drug trade. He also described Washington as an unreliable ally.

"Instead of helping us, the first to criticise is this state department, so you can go to hell, Mr Obama, you can go to hell."

Later on Tuesday he warned: "Eventually I might, in my time, I will break up with America. I would rather go to Russia and to China.''

Mr Duterte also revealed that the US had refused to sell weapons to Manila, but added that he would be able to buy them elsewhere.

"If you don't want to sell arms, I'll go to Russia. I sent the generals to Russia and Russia said, 'Do not worry, we have everything you need, we'll give it to you'.

"And as for China, they said, 'Just come over and sign and everything will be delivered'," President Duterte said.

Read more at BBC.