Australia could use its "important voice" in the Pacific to help change attitudes and end discrimination against LGBTQI people in the region.

Having joined the Mardi Gras parade in Sydney, the UK's special envoy on LGBTQI rights, Nicholas Herbert, has praised the federal government's effort to step up its promotion of human rights.

"Australia is in a very powerful position to influence change as a major player in the region," he told AAP.

"I do think Australia has an important voice."

The former conservative MP is visiting Australia to support gatherings of non-government organisations, officials and politicians who are committed to making change in the region.

Lord Herbert said while countries including Australia had legalised same-sex marriage, he was concerned about the nations where rights were "going backwards".

"All of this has been a reason to coordinate strategies, to talk about how we can work together to encourage steps in the right direction," he said.

Despite the lack of progress in some countries, Lord Herbert said he remained optimistic due to the growing list of countries decriminalising same-sex activity, and those legalising gay marriage.

"There is a sort of global generational change in attitudes towards LGBTQI rights," he said.

"We're not seeing it evenly reflected across countries and there are some other forces and pressures in the opposite direction."

Eight of the 14 states in the Oceania region have decriminalised same-sex acts, according to a report by the International Lesbian, Gay, Bisexual, Trans and Intersex Association.

Australia legalised same-sex marriage in 2017 after a majority voted in favour of marriage equality that year.

Homosexuality remains illegal in the Cook Islands, Kiribati, Samoa, Solomon Islands, Tonga, Tuvalu and Papua New Guinea.

Lord Herbert said he supported the acceptance of gay marriage by religious organisations, but it was ultimately up to the faiths to decide on the matter.

"When we passed the legislation in the UK, we ensured that religious organisations couldn't be compelled to conduct a same-sex marriage. I think that would have been quite wrong," he said.

"I respect the fact that it is their decision as a religious organisation and that's the essence of religious freedom."