The spike in claims to about 206,000 from 155,000 reflects the effects of the coronavirus outbreak on the state's economy, according to the Labor Department.
The state's unemployment website has been deluged with applicants, slowing it down and leading officials to ask people to try the site at off-peak times.
"No one will be denied one penny of their benefits," Murphy said Thursday.
The hardest-hit workers were from the food service industry, followed by those at doctors' and dentists' offices, the department said. Administrative workers were also hit hard.
A $600 supplemental unemployment benefit for workers that stems from the federal relief bill is set to begin for laid-off workers next week. It will be issued separately from regular jobless payments.
New Jersey is among the states hit hardest by COVID-19.
The state's death toll climbed by about 200 people to 1,700, Murphy said. The total number of positive cases topped 51,000, up from about 47,000.
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