For the reversible reaction 

${\mathrm{N}}_{2\left(g\right)}+3{\mathrm{H}}_{2\left(g\right)}\rightleftharpoons 2{\mathrm{NH}}_{3\left(g\right)}+\text{ heat }$

The equilibrium shifts in forward direction

As the forward reaction is exothermic and leads to lowering of pressure (produces lesser number of gaseous moles) hence, according to Le Chatelier's principle, at high pressure and low temperature, the given reversible reaction will shift in forward direction to form more product.