U.S. President Donald Trump and French President Emmanuel Macron have pledged to step up cooperation in the fight against Islamic terrorism and online radicalism.

The pair were holding a joint press conference on the eve of Bastille Day, an important national day marred by a mass-casualty terror attack in the French city of Nice in 2016.

Macron told the assembled reporters he had had a “long discussion” with the U.S. President, ranging over many different security challenges.

“When it comes to fighting terrorism, I can say from day one we have seen eye to eye and we are strongly determined to take any necessary measures to root out terrorism and eradicate it no matter where,” he said, mentioning measures to tackle online propaganda and cyber crime in particular.

President Trump took the opportunity pay his respects to the victims of the Nice attack, recalling that, “Tomorrow will mark one year since a joyous Bastille Day celebration turned into a massacre.”

“We all remember that – how horrible that was. We mourn the 86 lives that were stolen and we pray for their loved ones.

“We also renew our resolve to stand against these enemies of humanity, and to strip them of their territory, their funding, their networks, and their ideological support,” he pledged.

President Trump indicated that he and Macron had discussed ways their countries could “strengthen [their] vital security partnerships” in meetings with generals and other representatives from the armed forces and security services.

“France has excellent counter-terrorism capabilities,” he said. “French troops are serving bravely in places like Mali, to defeat these forces of murder and destruction. The United States and our allies strengthen our commitments to defeat terrorism.”

He also signalled that, unlike the Obama administration in Libya or the Bush administration in Iraq, he was determined that efforts to disrupt and destroy the Islamic State and related terror networks would not be undone by a lack of post-conflict planning, indicating that a strategy was being prepared to ensure that “victory would stay victory” this time.