Marine Le Pen, who is currently running for president in France, canceled a meeting with Lebanon's Grand Mufti after refusing to wear a headscarf for the occasion.
The far-right leader told reporters: "You can pass on my respects to the Grand Mufti, but I will not cover myself up."
The Grand Mufti's press office said that her aides had told her prior to the meeting that they required her to wear a head covering for the meeting.
Le Pen has been visiting Lebanon in a bid to bolster her presidential credentials.
She was scheduled to meet Grand Sunni Muslim Mufti Sheikh Abdel-Latif Derian on Tuesday morning.
Shortly after she arrived at his office, one of his aides tried to give her a headscarf to put on.
She refused and said she had met in the past with the grand mufti of Egypt's Al-Azhar, one of the world's top Sunni clerics, without wearing a veil.
Once she was told that customs are different in Lebanon, Le Pen walked toward her car and left.
Polls suggest Le Pen is likely to get the highest proportion of votes in the first round of voting in April, but then lose to a more mainstream candidate in the second round in May.