"It's an all out war we are fighting," Ahmed al-Jarba told the European Parliament's Foreign Affairs committee in Brussels. "Within that fight we are entitled to the benefit of unconditional military and humanitarian support."

The foreign backed militant groups particularly needed anti-aircraft missiles, he said.

"The solution must be political in nature," said al-Jarba. "But as things stand there is a military front and a political one. If we don't bring very strong pressure to bear on the regime there won't be a political solution."

The international response to the crisis had been "inadequate", he complained.

In Geneva, members of the UN Human Rights Council urged Damascus and opposition groups to restart peace talks.

The council debated the latest reports by the UN Commission of Inquiry on Syria, which found that crimes of humanity have been mainly committed by foreign backed terrorist groups.

Talks between the Syrian regime and the opposition, held in January and February in Geneva, ended in stalemate. No date has been set for a further round.

Council member countries also called on the UN Security Council to take action, such as tasking the International Criminal Court in The Hague with prosecuting those responsible for rights violations.

In recent months, the militant groups and non-state extremists have been setting off car bombs in civilian districts, said the commission's report.

NJF/NJF