The Duke and Duchess of Sussex have met the two baby koalas named in their honour at Taronga Zoo 

The ten-month old joeys were wedding gifts from the people of NSW for the couple, who got married in May - and just announced they were expecting their own baby.

The little joeys were unfazed by their royal visitors as their mothers, Wattle and Ruby, munched on eucalyptus leaves.

Meghan, showing just a hint of a baby bump, cooed at the koalas before stroking them, saying: "Sweet, cute” as keeper Suzie MacNamara explained how the animals are threatened in the wild.

The Duchess seemed very taken by the cuddly furballs and listened intently to Ms MacNamara before asking if she could stroke them.

The couple was presented with a koala toy for their new baby - a hastily arranged surprise for the couple after the news of their pregnancy yesterday.

It adds to their nursery's Australian-themed menagerie after they were given a stuffed kangaroo and joey by the Governor-General Sir Peter Cosgrove earlier on Tuesday.

Prince Harry - who has previously met koalas - was a tad more irreverent during the meeting.

“It’s not a drop bear, is it?” he joked as he was shown into the enclosure by Taronga Zoo CEO Cameron Kerr.

“No, they’re just a rumour for backpackers,” Mr Kerr replied, referring to the urban myth of dangerous, fang-toothed koalas that drop from trees with which Aussies often tease visitors.

The then walked to the new Taronga Institute of Science and Learning holding hands, inspecting quokkas and wallabies before heading into the koala enclosure.

The Institute, the largest of its kind in the southern hemisphere, will have five science lab rooms, three student classrooms, and will house part of Taronga’s “breed-to-release” program.

In front of hundreds of Taronga staff, donors, young volunteers and NSW Premier Gladys Berejiklian, Meghan used golden scissors to cut a line of green tape to open the centre. 

Prince Harry then unveiled a plaque commemorating their visit, who said the institute was "absolutely amazing.”

“Zoos in the 21st century have to modernise with everything else that’s going on. Taronga Zoo seems to be leading the way," he said

Cameron Kerr, the director and chief executive of Taronga Conservation Society Australia, welcomed the couple to Cammeraygal land, while Lille Madden, a 23-year-old traditional owner from the Gadigal people, said the welcome to country on behalf of local elder Dennis Foley.

“The 600 staff and about 3500 animals are excited to have you both here to mark this really important occasion,” Mr Kerr said.

“What this marks is Taronga’s absolute commitment to wildlife conservation, research and education. It’s a really important thing for the next generation."

The Institute is part of the Taronga Conservation Society Australia, which operates the zoo and also Taronga Western Plains Zoo at Dubbo, in central western NSW.

Taronga’s breed-to-release programs, and the rehabilitation work at its two wildlife hospitals, have so far released more than 50,000 animals into the wild.

The royal couple then boarded the Admiral Hudson, making the the rough 15 minute journey to the Man O‘ Warf Steps at the Opera House.