Hezbollah will ignore the verdict due next week by a UN-backed court on the 2005 murder of former Lebanese premier Rafic Hariri, the movement's leader said Friday.

The Special Tribunal for Lebanon is expected to hand down its verdict on Tuesday to four suspects, who were all being tried in absentia and are alleged members of Hezbollah.

"We do not feel concerned by the STL's decisions," Nasrallah said in a televised address.

"For us it will be as if no decision was ever announced," he said. "If our brothers are unjustly sentenced, as we expect, we will maintain their innocence."

Nasrallah has repeatedly expressed similar views completely rejecting the jurisdiction and independence of the court, which is based in The Netherlands.

The slain former prime minister's son Saad Hariri, himself a former premier, is expected in The Hague for the verdict.

The four defendants went on trial in 2014 on charges including the "intentional homicide" of Hariri and 21 others, attempted homicide of 226 people wounded in the bombing, and conspiracy to commit a terrorist act.

Nasrallah warned that "some will attempt to exploit the STL to target the resistance and Hezbollah" but urged his supporters to be "patient" when the verdict is announced.

Observers have voiced fears that the verdict, whichever way it goes, could spark violence on the streets of Lebanon between Hezbollah and Hariri supporters.