America has to ask itself difficult questions about why there are so many crimes committed by people using firearms, Prime Minister John Key says.
The United States experienced its deadliest mass shooting in recent history at the weekend, when gunman Omar Mateen shot dead 49 people inside the Pulse nightclub in Orlando, Florida.
Mr Key has written to US President Barack Obama to express New Zealand's sympathies. But he said there were now hard questions to ask over gun control.
"Why there are so many attacks of this nature, using weapons. But that's been a longstanding debate about gun control and the proliferation of guns in the United States.
"But you certainly wouldn't want to turn it into an issue about people's religion or ethnic beliefs."
Mr Key said the motivations for the attack in Orlando are not yet clear, and he did not have enough information to label it a homophobic attack.
"I just don't know enough, other than seeing the media reporting, to comment what's driving the person. I think they're questions that are being asked, but it's a gay club and maybe that's part of the driving motivation.
"Whether it was that or trying to make some statement of ISIS I just can't confirm that."
But Labour leader Andrew Little said there was no question in his mind.
"It clearly was, this is a guy who, according to the reports, clearly had difficulty accepting the right of people to express their sexuality, he chose a gay nightclub, he killed gay people."
There has also been debate in the US about whether the attack by Omar Mateen was driven by his religious beliefs.
Mr Obama said there was no evidence the gunman was part of a larger plot, and he described the attack as an act of home-grown extremism.
However, Republican candidate Donald Trump reiterated his call for a temporary ban on Muslims entering the country. He said it could be lifted once they were properly screened.
"We must find out what is going on," Mr Trump said in speech in New Hampshire... "We need to tell the truth about how radical Islam is coming to our shores."
Mr Key said Mr Trump's comments came as no surprise.
"It's been a big part of Donald Trump's so far, I don't think any of us would be terribly surprised he's beating that drum today."
Mr Key said there was no heightened security threat in New Zealand as a result of the Orlando shootings, but there was always the risk of a lone wolf attack in any country.