SINGAPORE (BLOOMBERG) - Auckland Airport has experienced a bounce in international visitor numbers, and is optimistic of further increases as New Zealand eases border restrictions, Chief Executive Officer Carrie Hurihanganui said.

Foreign arrivals at the nation's busiest airport plummeted when the border was shut in March 2020, but have started to recover following the removal of self-isolation requirements for residents returning home and, from last week, for visiting Australians.

That's welcome news after international passengers numbers fell to 5 per cent of pre-Covid-19 levels in 2021.

"We've already seen that go from 5 per cent to 20 per cent of pre-Covid, just in the last month as those restrictions have started to ease," Ms Hurihanganui said in a Bloomberg TV interview on Tuesday (April 19) during a visit to Singapore. "We're incredibly optimistic."

From May 2, New Zealand removes restrictions on arrivals from visa-waiver countries such as Singapore, Japan and the US.

Other travellers, including from China, can provisionally enter from October provided their home governments allow it.

Prior to the pandemic, the tourism industry made up 5.5 per cent of the country's economy.

Chinese visitors were a particularly lucrative market, accounting for 11 per cent of international guests while providing 15 per cent of tourism spending.