HANOI - Vietnam on Thursday asked for international support in its struggle against "terrorism", stepping up its justification for the arrest of a human rights lawyer.

Almost two weeks after the arrest of Le Cong Dinh for "propaganda" against the communist state, the Ministry of Foreign Affairs took the unusual step of releasing to foreign correspondents a three-page statement justifying the government's action.

Dinh's arrest has sparked concern from European countries, the United States, a global association of lawyers, human rights watchdogs and press freedom groups around the world.

"Vietnam wishes to seek understanding and support for its struggle against conspiracies and acts conducted by organisations and individuals to carry out acts of terrorism and unrest, overthrow the state and destroy the peaceful life of the people," the ministry said.

The statement repeated charges relayed through state-controlled media and was accompanied by an alleged confession in writing and on video.

"Le Cong Dinh used democracy and human rights as a cloak to carry out his subversive plots," the statement said.

Carl Thayer, a Vietnam specialist with the Australian Defence Force Academy, has said the "orchestrated press campaign" against Dinh signalled the seriousness with which the regime views the case, although exactly why is unclear.

Dinh colluded with exile Vietnamese organisations "in an attempt to prepare for riots and cause social instability and public disorder," foreign affairs said.

Last week the government said Dinh had confessed to participation in a training course in non-violent struggle held in Thailand by the US-based Viet Tan. Also known as the Vietnam Reform Party, the group says it wants peaceful democratic change but Vietnam calls it a "terrorist group".

Even after Vietnam fought foreign aggression for 30 years to secure its independence, "hostile forces have not given up their political ambition and they keep setting up new organisations from abroad" with the aim of overthrowing the state, the statement said.