短语讲解：

1. The United States has proposed a discussion with North Korea in connection with three Americans detained in that country.

in connection with 与…有关，连同
例句：That is a problem in connection with the military affairs. 
那是一个和军事有关的问题。 

2. The agreements call for setting up an industrial park in Gujarat state.

set up 建立
例句：They set up many branches throughout the country. 
他们在全国建立好多分公司。 

3. Relations between the two have been strained by a long-term border dispute and distrust about each other's military strength.

each other 互相
例句：All things are interrelated and interact on each other. 
一切事物互相联系并相互作用。