In a joint statement released Thursday, the governments of both states said a "neutral force" would be deployed by the Indian government in disputed areas.
"For this purpose, both the states shall not send their respective forest and police forces for patrolling, domination, enforcement or for fresh deployment to any of the areas where confrontation and conflict has taken place", the statement read.
Mizoram was part of Assam until 1972 and became a state in its own right in 1987.
The two states have been wrangling over their border for decades, but such deadly escalations are rare.
The government of Mizoram Thursday also expressed regret -- for the first time since the clashes -- over the death of the six police from Assam.
Last week, the chief ministers of both states tweeted that they would seek an amicable approach to the dispute.
Assam chief minister Himanta Biswa Sarma belongs to Modi's ruling Bharatiya Janata Party while Mizoram chief minister Zoramthanga heads the Mizo National Front -- an ally of the ruling BJP alliance.