Under the policy, illegal immigrants are released from detention while awaiting a court hearing on their status.
Ending "catch and release" was one of Trump's central promises during the 2016 campaign, but immigration authorities have faced a shortage of space to house people who have been detained.
Among the measures outlined in the memo, Trump directed the departments of Defence and Homeland Security to produce a list of military facilities that could be used to detain illegal immigrants.
Earlier on Friday, pointing to an upswing in border crossings to levels seen during former President Barack Obama's tenure, Sessions ordered US attorneys offices near the Southwest border to prioritise bringing cases against first-time offenders.
Once border crossers are charged with illegal entry and deported, they can be charged with a felony carrying significant jail time if they are caught crossing illegally again.
Some federal prosecutors, defence attorneys and judges have expressed concerns that charging border crossers en masse is a drain on court resources.
But supporters of Session's approach have said that criminal penalties deter repeat crossers, while detractors have said the prosecutions can deny legitimate asylum seekers the ability to properly file claims.
A Pentagon memo has also recommended the deployment of up to 4000 National Guard troops. It said the troops "will not perform law enforcement activities or interact with migrants."
The United States has sent military to the border a number of times over the years.
Sessions directed the US attorneys offices in southern California, Arizona, New Mexico and Texas to prosecute all the cases referred to under the criminal entry statute, known as 1325, "to the extent practicable."
