"The most critical thing they can do on the economic side is actually get an IMF agreement," Blinken said in response to a question at a Senate hearing.
"We would strongly encourage them to do that because the economy risks falling off the deep end," he said.
Tunisia has been struggling under mounting debt and rising prices worsened by Russia's invasion of Ukraine. It reached an agreement in principle in mid-October for a nearly $2 billion package from the International Monetary Fund.
The international lender has sought reforms in Tunisia and more recently has voiced alarm over a wave of racist attacks after remarks by President Kais Saied against "illegal migrants" from sub-Saharan Africa.
European Union foreign policy chief Josep Borrell warned Monday that Tunisia risks collapse "economically or socially" that could trigger a new flow of migrants to Europe -- an assessment rejected by Tunis.
Blinken also renewed concerns about the political turn of Tunisia under Saied, who consolidated power in 2021 and has since granted himself almost limitless powers.
The opposition has accused Saied of mounting a coup in the country that had been the birthplace of the Arab Spring democracy movement a decade earlier.