"We must act. We must take all necessary steps to protect our population and our territories, because no country is safe," Hollande said, while addressing a joint press conference with Merkel.
The Socialist leader who called for an international coalition to uproot militants, urged Germany to "engage further in the fight against Daesh in Syria and Iraq", Xinhua news agency reported.
"If Germany could go further, it would be a very good signal in the fight against terrorism," he stressed.
For her part, Merkel said 650 German soldiers would be deployed in Mali to back the French-led peacekeeping mission in the West African country. The decision also aimed at easing pressure on French forces in the Sahel region following its military commitment to fight IS.
"We can not defeat Daech with words. It needs military means. But, at the same time it's necessary to find a sustainable solution for Syria via political means," the German Chancellor said.
Merkel on Wednesday flew to Paris to pay tribute to the 130 people killed in the recent attacks that rocked French capital and also to support France's military and diplomatic offensive to defeat the Islamic State (IS) which claimed responsibility of the November 13 suicide bombings and shootings.
In the wake of France's worst terrorist attacks, Hollande held a series of meetings with major countries' leaders to seek support for building a "strong and global" diplomatic front to beat IS.
Vowing merciless war against terrorism, he opened this week's intensive diplomatic appointment with talks with visiting British Prime Minister David Cameron before flying to Washington where he met President Barack Obama to step up strikes against IS.