It led to the country's largest demonstrations since the fall of communism in 1989.
Though his role is largely ceremonial, the president's powers include nominating the prime minister after elections and returning legislation to parliament for reconsideration. "Romania needs a government that governs transparently, predictably, not at night in secret", Iohannis said, in a reference to the government passing an emergency decree at midnight on January 31.
"You have been saying in public that I would like to overthrow the legitimate government".
"Romania needs a strong government, not one that shyly executes party orders", said Iohannis, a former leader of the centre-right opposition.
BUCHAREST, Romania Romania's government is on a high-risk mission: devise a legal and politically acceptable way to remove penalties for some types of official corruption.
"The resignation of a single minister is too little and early elections would at this stage be too much".
Romania, a country of 20 million people which hosts a US ballistic missile defence station and is one of Washington's staunchest allies with troops in Iraq and Afghanistan, remains among the poorest, most corrupt members of the European Union. "That's false. You won, now you govern and legislate, but not at any price", Mr Iohannis said. "This is the available room for maneuver".
No member of the coalition government attended the president's speech, while MPs from PSD and ALDE exited the chamber in sign of protest.
Romania, a country of 20 million people and host to a USA ballistic missile defense station, remains one of the poorest and most corruption-ridden members of the EU.
Local television stations reported that protests across Romania attracted 500,000 to 600,000 people - with at least half of them gathering in Victory Square, Bucharest.
On Monday evening, he was the target of counter-protests who gathered in front of his headquarters to back the government and demand his resignation.
The corruption decree, issued late in the evening of January 31 by the cabinet without parliamentary debate, had been created to decriminalise a number of graft offences, cut prison terms for others and narrow the definition of conflict-of-interest.
Tens of thousands protested across Romania on Monday evening against the social-democratic government led by Prime Minister Sorin Grindeanu, even after a controversial decree was repealed, local media report.
Political analysts said the government - in power for barely a month - now faced an uphill task restoring shattered public confidence. "This is what the street would like to see".
Liviu Dragnea, leader of the PSD, would have been a major beneficiary of the decree.
"The governing programme is good", said Mr Dragnea, whose current trial on abuse-of-office charges would have been halted by the decree. We are exhausted of the same old things.