Australian Prime Minister Malcolm Turnbull said the police shooting of Justine Damond is "shocking" and "inexplicable".
"How can a woman out in the street in her pyjamas seeking assistance from the police be shot like that?" he asked on Australia's Today Show.
"It is a shocking killing, it is inexplicable...we are demanding answers on behalf of her family and our hearts go out to her family and all of her friends and loved ones."
The US officer who shot and killed Damond is refusing to cooperate with investigators. Mohamed Noor shot the 40-year-old yoga instructor outside her home in Minnesota on Saturday, after she called police to report a possible assault.
Minneapolis Mayor Betsy Hodges has called the incident a "needless" and "tragic" death and says the community is reeling. She says there is a stack of unanswered questions about what exactly occurred, and has urged the officer to voluntarily make a statement.
"We cannot compel Officer Noor to make a statement, I wish we could. I wish that he would make a statement is what I want to say," she said. Ms Hodges wants answers about why he fired at Damond, what happened once officers arrived on the scene and why the police did not activate their body cameras.
According to the Minnesota Star Tribune police arrived at the scene and heard a "loud noise", possibly fireworks, before Damond approached Officer Matthew Harrity who was in the driver's seat. At that point Officer Noor fired and shot Damond in the abdomen. The officers performed CPR but she was pronounced dead 20 minutes later.
The American Civil Liberties Union (ACLU) says that the Minnesota police officers violated their code of conduct by failing to turn on their body cameras before the incident and after the use of force.
Spokesperson Teresa Nelson said "This violation of policy thwarted the public's right to know what happened to Ms. Damond and why the police killed her."
"We call for the release of the audio from the 911 call that she made, along with any audio from the dash camera. Even if the dash camera did not capture images from incident, it may have picked up audio."
Ms Damond's heartbroken fiancé Don Damond, who she was due to marry next month, feels he has been totally left in the dark by the authorities. "Our hearts are broken," he said in a news conference on Tuesday. He said Damond had called police to report a possible sexual assault near her home. "Sadly, family has been provided no additional information from law enforcement regarding what happened after police arrived."
He said Damond's family and friends were desperate for information.
According to a Washington Post database, 963 people were shot and killed by US police in 2016, and 547 have been shot and killed so far in 2017.