HSBC has said its performance in parts of Europe and the US was "not acceptable" as the bank reported a drop in third quarter profits.
Europe's largest bank said profit before tax fell 18% to $4.8bn (£3.8bn) in the three months to September, missing analysts' estimates.
In a statement, the bank also warned of a "challenging" environment ahead.
HSBC has been navigating uncertainty arising from Brexit, the US-China trade war and ongoing unrest in Hong Kong.
Noel Quinn, who took over as HSBC's acting chief executive after the shock departure of John Flint in August, praised the performance in Asia but criticised other regions.
The bank makes most of its profits in Asia.
"Parts of our business, especially Asia, held up well in a challenging environment in the third quarter," said Mr Quinn.
"However, in some parts, performance was not acceptable, principally business activities within continental Europe, the non-ring-fenced bank in the UK, and the US."
Mr Quinn said previous plans to improve the performance of these businesses were "no longer sufficient" and that they are "accelerating plans to remodel them".
HSBC's dual nature - listed in London and Hong Kong and standing astride the trade flows between east and west - has often been a source of comfort for investors, who like a bank that doesn't have all its eggs in one basket.
It has also, however, been a source of discomfort for the bank and its shareholders. A dozen years ago, activist investor Knight Vinke led a campaign against HSBC's board, accusing it of corporate governance failings and urging it to stop spending money on western markets and concentrate on Asia, where there were more and more profitable opportunities for growth.
Fast forward to today and those same themes run through the first financial results from Noel Quinn, the bank's interim chief executive.
Mr Quinn, a battlefield promotion after the abrupt departure of John Flint in August, is clearly making his pitch for the getting the job full-time.
Statements from bank chief executives are normally bland in the extreme, but Mr Quinn pulls no punches, saying performance in the UK (notably the retail bank), Europe and US was "not acceptable" and that restructuring plans to focus on the Asian operations would be accelerated.
The bank has also warned there will be one-off financial hits in the next quarter to pay for the restructuring - which is likely to be shorthand for big job cuts to come.
The Financial Times reported earlier this year that HSBC would cut as many as 10,000 jobs; given the language in which Mr Quinn has couched his warnings about the bank's performance, that looks a likely outcome.
The bank also said the revenue environment was "more challenging" than in the first half of the year, and predicted "softer" revenue growth than previously anticipated.
It also warned of "significant charges" in the fourth quarter - including those related to restructuring - if the backdrop worsened further.
While HSBC warned earlier this year that profits would be hit by a slowdown in China, the broader region was profitable for the bank in the third quarter.
The bank said profit before tax in Asia rose 4% to $4.7bn in the period, citing "resilience" in Hong Kong.
It follows months of unrest in the territory that have raised concerns about the impact on the economy and the reputation of the Asian financial hub.
BDST: 1516 HRS, OCT 28, 2019