The artistic swimming Olympic qualification event due to be held in Tokyo in March has been postponed until May because of novel coronavirus restrictions in Japan, organizers said on Thursday.

Tokyo 2020 organizers and swimming's world governing body FINA said the qualifier, which also doubles as a test event for this summer's Tokyo Games, would take place from May 1-4 instead.

"The decision to postpone was taken for a number of reasons including assisting the ongoing efforts in Japan to come out of the current situation as soon as possible," they said in a joint statement.

With much of Japan under a state of emergency battling a third wave of COVID-19 infections, the country has effectively shut its borders to foreign non-residents.

Initial restrictions allowed foreign athletes to come to Tokyo for Olympic test events and training but that was changed earlier this month.

The postponement of the qualifying event comes amid dwindling public support for the 2020 Games, which have already been delayed by a year due to the pandemic.