Maine began issuing a new federal unemployment benefit of $300 a week to many jobless workers Friday, but the extra financial assistance will not last long.

Eligible claimants began receiving payments on Friday evening, according to the Maine Department of Labor. The benefits will be retroactive to the week ending Aug. 1, and the initial round of checks will cover benefits through the third week ending in August, a payment of up to $900.

The Lost Wages Assistance Program, authorized by a presidential order in early August, will provide states with enough money to cover payments for six weeks before expiring, the department said. Maine received $134.8 million.

That means it will pay out benefits owed up to the week ending Sept. 5 but no later. Funding, from a Federal Emergency Management Agency disaster relief fund, already has run out for some states that were the first to implement the program. Roughly 85,000 people in Maine are potentially eligible for added unemployment pay for at least one week, according to the department.

The limited relief was supposed to be a stopgap measure while Congress negotiated a longer-term added benefit for jobless workers. A $600-per-week supplemental benefit authorized by the federal CARES Act expired in late July.

“While we appreciate that temporary funds have been made available, we continue to hope that Congress will step up to provide comprehensive long-term support to Maine people during these challenging times,” said Maine Labor Commissioner Laura Fortman in a statement.

Not everyone who collects unemployment benefits will receive the added payment. Laid-off workers must be eligible for at least $100 a week in benefits and be fully or partially unemployed as a direct result of the coronavirus pandemic.

At least 1,200 Mainers will be excluded from the program because they do not collect enough from unemployment, according to the state labor department. It is not certain how many others will lose out because the FEMA program defines being out of work because of the pandemic differently than unemployment programs set up by the CARES Act six months ago, said labor department spokeswoman Jessica Picard. Eligible recipients will receive a letter in the mail and online correspondence, Picard added.

New and continuing claims for unemployment have fallen sharply since the height of state-ordered shutdowns and business closures this spring, but they remain at a historic high. There were almost 35,500 claims filed for continued state jobless benefits last week, higher than any point prior to the pandemic in the past 17 years.

Combined with new federal unemployment programs enacted by the CARES Act in March and an extension to the eligibility period for state unemployment that allows claimants to receive benefits for up to a full year, there were about 66,000 claims for continued benefits filed in Maine during the same week.

That figure represents about 10 percent of the state’s civilian workforce.