9/11 was unprovoked by US: Howard

Former prime minister John Howard believes it is worth reminding people 9/11 was an unprovoked attack on the United States by a group of terrorists.

Former prime minister John Howard feels it is necessary to remind people America had done nothing wrong to provoke the 9/11 attacks on the United States by a group of terrorists..

"That was an unprovoked, unjustified attack on the United States, America had not done anything wrong to deserve that," Mr Howard told Sky News on Sunday.

Mr Howard, who was in the US in 2001 when the attack occurred, will attend a public remembrance service service in Sydney with US ambassador John Berry 15 years after the event that killed nearly 3000 people .