I wish to know if it is possible to express the n-qubit Hadamard unitary square matrix of size $2^n * 2^n$ as a product of 'k' two-level unitary square matrices where 'k' is of the order of polynomial in 'n'. By order is meant the Big-O notation of computational complexity theory. By the 2-level matrix, I mean the definition in the book "Quantum Computation and quantum information" by Nielsen and Chuang, section 4.5.1 "Two level unitary gates are universal", pp. 189. A two-level unitary matrix is a unitary matrix which acts non-trivially only on two-or-fewer vector components.
I also wish to know if the same decomposition into 'k' two-level unitary square matrices can be done to a Quantum Fourier Transform (QFT) unitary square matrix of n-qubits of size $2^n * 2^n$ where 'k' is of the order of polynomial in 'n'.
I have read that the two-level unitary gates/square matrices are universal.
Any help in this regard is highly appreciated.