Prime Minister John Key has favourably compared his efforts in raising human rights during a recent trip to Saudi Arabia with United States President Barack Obama, who he said did not raise human rights during his visit.

Asked by Green MP James Shaw whether he would make a preferential free trade deal conditional on human rights being improved and beheadings stopped in Saudi Arabia, Key said he had an extensive discussion with King Salman bin Abdul Aziz during his recent visit.

"We did not only raise it and have a reasonably extensive discussion, but we did more than President Obama did who didn't actually raise human rights when he went to Saudi," Key said.

Obama led a bipartisan US delegation to Saudi Arabia in January after the death of King Abdullah.

There he held an hour-long meeting with King Salman during which they discussed a range of issues including the campaign against Islamic State.

A BBC report, citing US officials, said Obama "stressed the importance of human rights" but did not raise the case of Saudi blogger Raif Badawi, who had been sentenced to 1000 lashes and 10 years in jail for "insulting Islam through electronic channels" and "going beyond the realm of obedience".

Key told reporters later that his main point was that New Zealand had a very proud record on human rights and had raised it and New Zealand had nothing to be ashamed of.

President Obama was criticised for not doing it, Key said.

Engagement with Saudi Arabia, and others where NZ would like to see significant improvement, the only way was to visit and grow a closer relationship.

Engagement or isolation were the only two options and he was in favour of engagement.

He said he would be "amazed if it gets across the president's desk" that he had made the comments.