London: Australia, the UK, US, New Zealand and Canada are pushing to force technology companies to co-operate with intelligence agencies by giving them "lawful access" to encrypted messages through a "back door" in exceptional cases so that they can catch serious criminals and terrorists.

The countries, which form a group known as Five Eyes, met for two days in London hosted by new British Home Secretary Priti Patel and Attorney-General Geoffrey Cox.

Intelligence agencies say end-to-end encryption on WhatsApp hinders their investigations. Credit:Shutterstock

Patel says although encryption is important in protecting citizens' privacy, it has to be set against the rising online threat of terrorism and extremism and a tenfold increase in online child sexual exploitation and abuse since 2013.

The Five Eyes official communique at the end of the meeting agreed: