The phrase "acknowledged the challenge of" is correct and usable in written English.
You can use it when discussing recognition of difficulties or obstacles in a particular situation or context.
Example: "The committee acknowledged the challenge of implementing the new policy effectively."
Alternatives: "recognized the difficulty of" or "admitted the struggle with".
She acknowledged the challenge of starting a new foundation in the current economic downturn.
In the preface he wrote for the first Chinese edition of Alice, Chao acknowledged the challenge of translating the book.
In a recent e-mail from Germany, Mr. Schlichtig acknowledged the challenge of working with Mr. Fuchs.
Mr. Brown acknowledged the challenge of increasing annual development aid by $50 billion but said it was an achievable target.
She acknowledged the challenge of such an undertaking, as it requires a change in the way people and society view young-old interactions and relationships.
On the subject of guns, he acknowledged the challenge of pursuing gun control in the face of political opposition from those same Reublicans.
Jason O'Donnell, the Corzine campaign's field director in Hudson County, acknowledged the challenges of transferring support for Mr. Obama to the governor.
As shareholders and analysts wait for Google to find the next product to reignite revenue growth as the core search business slows, Mr. Page acknowledged the challenges of building new products that reach people on the same scale as search.
In a recent post for the Hive Learning Network NYC, which has provided support for Kickflip, Bar-Zemer acknowledged the challenges of designing an educational program "for youth who do not ordinarily participate in structured learning activities".
The local police chief in the Buner district, Zubair Shah, a rising star of the Pakistani police force, acknowledged the challenges of confronting a Taliban threat that is more deeply ensconced in communities all over Pakistan than had been thought.
