  The main limiting factor of cosmological analyses based on thermal
Sunyaev-Zel'dovich (SZ) cluster statistics comes from the bias and systematic
uncertainties that affect the estimates of the mass of galaxy clusters.
High-angular resolution SZ observations at high redshift are needed to study a
potential redshift or morphology dependence of both the mean pressure profile
and of the mass-observable scaling relation used in SZ cosmological analyses.
The NIKA2 camera is a new generation continuum instrument installed at the IRAM
30-m telescope. With a large field of view, a high angular resolution and a
high-sensitivity, the NIKA2 camera has unique SZ mapping capabilities. In this
paper, we present the NIKA2 SZ large program, aiming at observing a large
sample of clusters at redshifts between 0.5 and 0.9, and the characterization
of the first cluster oberved with NIKA2.
