Restricting energy imports and total primary energy supply are the two direct policy options used for the improvement of energy security. Restricting energy imports directly reduces energy import dependency, which leads to diversification of energy resources and ultimately enhances energy security, while total energy supply reduction affects energy security through the diversification of efficient technology mix and energy resources supply mix. This paper examines the effects of restricting energy import and primary energy supply on the diversification of energy resources, technology mix in energy, supply-side and demand-side, energy efficiency, energy conservation and energy security during the planning horizon 2005-2050. The analysis is based on a long-term integrated energy system model of Pakistan using the MARKAL framework to analyse the long-term effects of different policy options during 2000-2035. The effects related to energy security are represented through a set of energy security indicators, such as energy import dependency, diversification of energy resources through DoPED and SWI, and vulnerability. The study finds that energy import dependency, diversification of energy resources, and vulnerability show an improvement under energy import restriction as compared to the base case. Diversification of energy resources and vulnerability improve under primary energy supply restriction as compared to the base case, while energy import dependency deteriorates under the primary energy supply case. Therefore, for the enhancement of energy security, restricting energy import is a better option than restricting primary energy supply.