From midnight tonight, additional restrictions and hefty penalties for non-compliance will apply to all international arrivals in NSW.

The state government has announced in addition to the Commonwealth restrictions on nine African countries, all other overseas travellers must complete a PCR test and isolate for 72 hours at a nominated address or accommodation.

Arrivals must take another PCR test six days after entering Australia.

Fines will be increased from $1,000 for individuals to $5,000, and from $5,000 for corporations to $10,000.