Newcastle manager Eddie Howe admits success will take "a lot longer" to achieve for his club after a frustrating transfer window.

When Amanda Staveley helped complete the Saudi-backed takeover of Newcastle in 2021, she boldly claimed the Magpies could win the Premier league within a five to 10-year period.

But Newcastle's progress has stalled since they qualified for the Champions League at the end of the 2022-23 season.

Staveley sold her minority shareholding in Newcastle during the close season and, while the Saudi wealth remains, Howe has found it difficult to splash the cash of late.

Efforts to strengthen his squad have been hampered by the Premier League's profitability and sustainability rules, with Crystal Palace's England defender Marc Guehi remaining beyond their grasp as the transfer window prepared to shut on Friday evening.

Asked on Friday if the club's fans had been sold a false dream of future success, Howe said: "I don't think the dream dies, necessarily, but I think it takes a lot longer.

"We've got to build our revenue streams, that is the biggest thing. We've got to bring more money into the football club however we do that, through player sales, through sponsorship, through loads of various things. 

"That's the big thing that we need to focus on now for the next, probably, 10 years.

"Whether I'm lucky enough to see any of that, who knows? But the dream is not over, it's just going to take a lot, lot longer."

Newcastle's owners have invested more than £400 million ($526 million) in the squad since their arrival on Tyneside, but have made just one major signing -- Italy midfielder Sandro Tonali -- in the last three windows.

Howe also had to sell Elliot Anderson and Yankuba Minteh in a bid to comply with PSR limits amid speculation over the futures of key players Bruno Guimaraes, Alexander Isak and Anthony Gordon.

Last season's seventh-place finish in the Premier League and exit from the Champions League group stage has increased the pressure on Howe to deliver this term.

He conceded Newcastle's transfer travails have hardly helped his cause.

"I'm not going to sit here and say it's been a brilliant transfer window for us. I think everyone will look at me and think, 'I'm not sure he's telling the truth there'. I do try as far as I can to tell the truth," he said.

"But it's not been through the want of trying from anybody's perspective and I think for me to sit here and say that would be totally wrong as well. Everyone has tried really, really hard to improve the squad to make sure we've got a chance of success."