North Korea has said it will put two US tourists on trial for committing crimes against the state, dimming any hopes among their families that they would soon be released.

"Their hostile acts were confirmed by evidence and their own testimonies," said the official KCNA news agency on Monday, referring to Jeffrey Fowle and Matthew Miller who are being held by the country.

It gave no details on when they would face court.

Fowle, a 56-year-old street repairs worker from Miamisburg, Ohio, was arrested after entering North Korea as a tourist in late April.

Miller, 24, was taken into custody after he ripped up his tourist visa and demanded asylum on entering the country, state media said.

Another US national, Kenneth Bae, a Christian missionary who had been arrested in November 2012, was convicted and sentenced to 15 years hard labour last year.

Pyongyang has arrested a number of US citizens in the past, using them to extract visits by high-profile figures, including former US President Bill Clinton.

But it has twice cancelled visits by Robert King, the US special envoy for North Korean human rights issues, to discuss Bae's case.

The KCNA announcement comes a day after Pyongyang fired two short-range ballistic missiles, defying a UN ban on the reclusive state testing such weapons.

North Korea periodically accuses the US of military hostility and conspiracy to overthrow its leadership.

Source: Reuters