Shipowners and seafarers are calling on the UN to help facilitate crew transfers as the Covid-19 pandemic spreads and many countries close their borders.

The International Chamber of Shipping (ICS) and the International Transport Workers' Federation asked the heads of four UN agencies to provide seafarers with the "key worker" status that airline crew and medical personnel have.

"They should be afforded special consideration and, notwithstanding the need to comply with emergency health protocols, treated with pragmatism and understanding when seeking to travel to and from their ships," the letter, to the IMO, International Labour Organization, UN Conference on Trade and Development and World Health Organization (WHO), read.

The industry group and the union asked that the agencies take up the matters with urgency. The two stressed that shipping carries 90% of all global trade, including medical supplies, and that roughly 100,000 seafarers need to be changed over from their ships.

Several shipowners, including AP Moller-Maersk and Torm, announced they had cancelled crew changes. Vessels are reportedly being asked to submit medical records to port authorities earlier. Further, as many as 20 ports are refusing ships that had docked in Italy, which on Thursday passed China as the worst-hit country.

"In this time of global crisis, it is more important than ever to keep supply chains open and maritime trade and transport moving," the letter read.

"In particular, this means keeping the world's ports open for calls by visiting commercial ships, facilitating crew changes and the movement of ships' crews with as few obstacles as possible."

The letter comes on the heels of an emergency ICS meeting on Thursday, specifically to deal with the issue of crew changes.

“This meeting will not be a ‘one-off’, but the beginning of a series of regular conference calls with our national associations in response to the significant challenge facing the world, our seafarers and the global shipping community," ICS secretary general Guy Platten said.

"We want to ensure that all the issues the industry is facing can be addressed together."

Worldwide, there were more than 191,000 confirmed coronavirus cases on Wednesday, according to the WHO, which was up more than 15,000 from Tuesday.

In Europe, which the WHO has identified as the epicentre of the pandemic, there were nearly 75,000 cases and more than 3,300 deaths.

This week, the EU sealed its borders. Italy went into lockdown on 10 March and was followed by France on 17 March.