"My main message will be that we must work even harder to counter violent extremism," Lidegaard said in a statement in which he added that Isis was "one of the biggest, if not the biggest security threat in recent times".
Lidegaard, who will visit Saudi Arabia and Iran, said on Friday at the NATO summit in the British city of Newport that Denmark was ready to join a coalition to fight extremists in Iraq and Syria suggested by US President Barack Obama.
In the statement, the foreign ministry explained that both "the regional actors' contribution to resolving the crisis, and how the international community can fight the growing threat of violent extremism" were on the journey's agenda.
Lidegaard is the first Danish foreign minister to visit Iran since 2005.
Isis, a Sunni extremist group, has gained prominence in recent months, declaring an Islamic "caliphate" in regions under its control in Iraq and Syria.