Clashes between the security forces and Sonko's supporters erupted after he was given a two-year sentence in a case he says was designed to stop him running for president next year.
Hundreds were injured and hundreds more arrested in two days of unrest from June 1-3.
It condemned what it called the "extremely serious attacks against the state, the republic and institutions", saying the violence aimed to "sow terror and bring our country to a standstill".
President Macky Sall asked the government to take steps to assist "the people and entities that have suffered harm", the statement said.
Sonko's conviction was the outcome of a two-year case for rape charges that transfixed the country, triggering sporadic unrest that had already claimed a dozen lives.
The 48-year-old former tax inspector has spoken out against debt, poverty, food insecurity, under-funded health and education systems and corruption.
Sonko has repeatedly claimed the government is trying to keep him out of the running, which it denies.
Supporters of Sonko and Sall have traded blame for the violence and deaths.