When ice melts into water at \(273\text{ K}\), it changes from solid ice to liquid water.
An important property of water is that ice has larger volume than the same mass of water.
So, during melting:
\[
\text{volume decreases}.
\]
That means the ice-water system contracts.
Atmospheric pressure acts on the system from outside.
Since the system contracts against atmospheric pressure, work is done on the system by the atmosphere.
Therefore, the work done on the ice-water system by the atmosphere is positive.
Also, heat is absorbed during melting as latent heat, so the internal energy does not decrease.
Hence, the correct statement is:
\[
\text{Positive work is done on the ice-water system by the atmosphere}.
\]