Cassis, in a phone conference with Germany, Austria, Luxembourg and Liechtenstein on Tuesday, said a coordinated effort was necessary to avoid a second wave of infections.
Cassis said working together was necessary to ensure the current health and economic crises did not become a social crisis in the months to come.
Essential in ensuring both Switzerland and its neighbours can emerge from the lockdown effectively is that social distancing measures be coordinated across borders.
“Now is the time to think about the best way to come out of the crisis – and the steps we need to take – in the coming weeks”.
By rolling out a uniform phasing out of social distancing rules, the countries could ensure the transition took place in a calm and effective manner.
In addition to coordinating on social distancing and other lockdown restrictions, Switzerland said it was imperative that border regions work together to ensure hospital resources were shared.
Germany has committed to treating patients from other countries, particularly hard-hit regions of Switzerland, Italy and France.