The British media reported on Wednesday that Trevor Birch revealed he would have "no option" but to liquidate the League One club by that deadline if agreement was not reached with the seven remaining senior players.
Both interested purchasers - former owner Balram Chainrai and the Portsmouth Supporters' Trust - have stipulated that their attempts to complete a takeover were dependent upon settlements being reached with those high earners.
"The facts are straightforward: under the terms of the offer for the club, the players have to leave and conclude compromise settlements," joint administrator Birch told reporters.
"This condition has been imposed by the Pompey Supporters' Trust as well as by [Chainrai's company] Portpin. Both interested parties have made it clear that they won't take on the club unless there is movement from the players.
"We will continue to do all we can to facilitate these deals but the club's future hinges on the willingness of certain players to sign up to compromise agreements that are affordable both in terms of the amount and timing of repayments.
"Unless we make significant progress on this front by August 10, then we are likely to have no option other than to close the club."
The deadline comes four days before a Capital One Cup tie against Plymouth and eight before Pompey are due to start their League One campaign at home to Bournemouth.
Birch has implemented a 5,000 pounds-a-week salary cap in an attempt to prolong the club's existence in the short term but long-term progress would require high earners to accept a compromise on the remainder of their deals.
Striker Kanu, who is in Nigeria, has lodged a claim for three million pounds in back pay and defender Tal Ben Haim claimed this week that he was due a similar amount in salary arrears, bonuses and the remainder of his contract.
The other players - David Norris, Greg Halford, Dave Kitson, Erik Huseklepp and Liam Lawrence - are all in talks aimed at reaching an agreement or smoothing their transfers away.
Portsmouth, who won the 2008 FA Cup, were deducted 10 points when they returned to administration last season and were duly relegated to League One, where they will begin with a further 10-point penalty.
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