B3 was expected to contribute to increased production in the second half at the operation, which was "nearing pre-incident mining rates" earlier this month after a deadly mudslide in February.
"With the receipt of the B3 permit, ore extraction activities will begin this quarter and ramp-up over the year," Adams said.
New Afton was expected to produce 52,000-62,000 ounces of gold and 56-66 million pounds of copper in 2021.
The company's Rainy River mine in Ontario, the site of an operational turnaround in 2020 and a COVID-19 outbreak in April, was due to produce 270,000-290,000oz this year.
Adams said earlier this month New Gold's focus remained on further optimising the performance at its operations and maximising free cash flow to enhance its financial flexibility.
The company had ended March with a cash position of US$131 million.
Adams said yesterday C-Zone development at New Afton continued to advance and C-Zone extraction was expected to begin in the second half of 2023.
New Gold had begun the permitting process for the C-Zone in the March quarter.
Its shares (TSX: NGD) gained 2.48% yesterday but are down 11.4% year-to-date.
Its close of C$2.48 puts its market cap at $1.69 billion (US$1.4 billion).