Man armed with knife fatally shot by police in western Sydney

A critical incident has been declared after police shot dead a man armed with knife in western Sydney overnight.

Emergency services were called to Bird Walton Avenue in Middleton Grange about 11pm yesterday.

Upon arrival, officers were allegedly confronted and threatened by a 34-year-old man with a knife.

Police said initial information indicated a 33-year-old male officer was struck with the knife but was protected by his operational vest.

A Taser was deployed and was ineffective.

The man was then shot by police.

Officers conducted CPR on the man until paramedics arrived, but he could not be saved.

A critical incident was declared and an investigation was launched into the circumstances surrounding the incident.

The incident will also be subject to an independent review.