Final answer:
Ivan IV's reign was characterized by the territorial expansion of Russian territories in the North-West, which included the annexation of various khanates and the colonization of new areas through Cossack recruitment.
Step-by-step explanation:
The foreign policy of Ivan IV, famously known as Ivan the Terrible, during his reign primarily involved the expansion of Russian territories in the North-West. This was a period marked by extensive territorial conquests which included the annexation of the khanates of Kazan, Astrakhan, and Siberia. Ivan IV recruited Cossacks to colonize new territories, expanding Russian influence. His reign laid the groundwork for further Russian expansion, which continued into the territories of modern-day Ukraine, the Caucasus, and beyond under subsequent rulers such as Catherine the Great.