Wales are set to face Japan before playing two Tests against New Zealand.

"Our [summer] Test matches look likely to be either cancelled or postponed until the end of the year," he said.

The domestic Japanese Top League has already been cancelled, with doctors warning the country's medical system could collapse because of coronavirus.

In New Zealand, Prime Minister Jacinda Ardern has announced an easing of lockdown restrictions.

New Zealand, which went into lockdown on 25 March, will ease domestic restrictions slightly on 27 April, but its borders remain closed to almost all foreign travellers.

Rescheduling June and July tour dates in the southern hemisphere to October is understood to be one of the options being considered by World Rugby.

Joseph, a former All Black and Japan forward, is currently on lockdown in New Zealand, leaving his plans for a new international cycle on hold for the country he steered to the quarter-finals of the 2019 World Cup.

"It's all up in the air when we can get back into Japan to prepare for those Test matches," he told the Pick up the Pace podcast.

"Once we get to understand what the [playing] landscape is like, we just plan accordingly."

Wales have previously toured Japan in 2001 and 2013, winning three out of four Tests.