After 1953, north korea and south korea sometimes discussed reunification but found it difficult to agree because they

had different political systems and aspirations

Explanation:

After the division of the Korean Peninsula in 1953, two nations were formed, North Korea and South Korea. The boundary between the two was on the place where the armies that supported the North and the ones that supported the South met.

North Korea became a communist country, while South Korea became a capitalist country. North Korea had the support and it was ally with the communist countries such as the Soviets and China, while South Korea had the support and it was ally with the Western countries.

There were talks on several occasions about reunification, but the politics were too big of a problem. None of the sides were willing to back off on their ideals, nor they wanted to make compromise, which understandably didn't do any good.

The two countries have been and still are in very bad relations, with constant threats of war, especially provoked from the North Korean side.