"Today I have offered my resignation to the president of the republic" Andrej Kiska, Fico said in a public address yesterday. "If the president accepts it, I am ready to resign tomorrow."
Fico, 53, has been struggling since February with a scandal over the killing of journalist Jan Kuciak and his fiancee.
The killing had sparked protests against Fico's government, with tens of thousands of Slovaks turning out for rallies.
The prime minister's three-party coalition government was facing a no-confidence vote by lawmakers scheduled for next Monday.
But a minor member of Slovakia's three-way governing coalition, the Most-Hid party, raised the pressure further, calling for early elections.
Kiska had also called for early elections -- or sweeping government changes -- earlier this month.
Fico has resisted the call for snap polls. He warned the country could "plunge into chaos if the current opposition takes power".
Kuciak and his fiancee Martina Kusnirova, both 27, were found shot dead on February 25 at their home near the capital Bratislava.
Police said Kuciak's death was "most likely" related to his investigation on ties between Slovakia's top politicians and Italy's 'Ndrangheta mafia.
The murder and Kuciak's article, published after his death, sparked a wave of anti-government sentiment in Slovakia, an EU and NATO member of 5.4 million people.
The EU urged Slovakia to swiftly investigate the murder.
"The top priority for all of us must be to carry out an independent and thorough investigation of the facts and bring those responsible to justice," the EU's security commissioner Julian King told MEPs in Strasbourg today.
"We call upon the Slovak authorities to do this quickly."
The killing of Kuciak and Kusnirova raised fresh concern about media freedom and corruption both in Slovakia and Europe.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)