"Iran and Iraq are two nations whose hearts & souls are tied together through faith in God, love for Imam Hussein and the progeny of the Prophet (PBUH). This bond will grow stronger day by day," the Leader's official Twitter account cited Ayatollah Khamenei as saying on Sunday.
"Enemies seek to sow discord but they’ve failed and their conspiracy won’t be effective," the tweet added.
The Leader's remarks comes as millions of pilgrims from Iraq, Iran and around the world are preparing to travel to the holy Iraqi cities of Najaf and Karbala to attend Arba'een, marking the 40th day after the martyrdom of the third Shia Imam, Hussein ibn Ali (Peace be upon him).
The gathering usually attracts more than 20 million participants every year.
Iraqis take pride in hosting pilgrims participating in Arba'een, many of which are from Iran. The event has consequently turned into a symbol of unity between the people of the two countries who deeply venerate Imam Hussein.
'US plot' in Iraq
The comments also come against the backdrop of several days of protests against mismanagement and corruption in Iraq, with certain demonstrations descending into violence and bloody clashes.
Speaking on Sunday, Iraq Interior Ministry spokesman Major General Sa'ad Ma'an Mousavi said a total of 104 people have lost their lives as result of the unrest.
More than another 6,000 have also been injured, he added.
Iraqi officials have claimed that "unidentified snipers" have shot at protesters and security forces in a bid to provoke clashes between the two.
Some Arab media outlets and observers have said that US-backed elements are trying to influence protests in a bid to create instability and push certain political agendas in the country.
Last week, the Lebanese Arabic-language daily newspaper al-Akhbar reported that Iraqi security sources have uncovered a US-backed plan seeking to install a pro-Washington government in Baghdad by provoking internal strife and instability in the country.
Also on September 18, Ayatollah Khamenei said enemies had been struggling to drive a wedge between the Iranian and Iraqi nations but have failed as the two neighbors are bound together by commonalities, particularly faith.
“Enemies have been making considerable efforts to sow discord between the two nations, but thank God they have failed and will fail from now on too, because the main factors binding the Iranian and Iraqi nations are their faith in God and love for the household of Prophet Muhammad (PBUH) and [his grandson and the third Shia Imam] Imam Hussein (AS),” the Leader said.
Ayatollah Khamenei made the remarks in a meeting with a number of Iraqi Moukeb (roadside station) holders serving pilgrims of Imam Hussein who head to the holy Iraqi city of Karbala from across the world each year to commemorate Arba’een, which marks 40 days since the martyrdom anniversary of Imam Hussein.
The Leader thanked the Iraqi nation for hosting and warmly receiving the pilgrims and the Iraqi government and officials for ensuring security during the mourning rituals.
Ayatollah Khamenei described the Arba’een march as an unprecedented event of global significance, which could lay the groundwork for the establishment of a modern Islamic civilization.
The Leader said the Arba’een march is the manifestation of Ashura some 1, 400 years after Imam Hussein was killed.
Pointing to Islamic awakening among Muslim nations, Ayatollah Khamenei commended the Iraqi nation as a great, dignified and civilized nation with a strong willpower and said, “The Iraqi youths showed their power … and managed to foil a big plot of Daesh and other Takfiri [terrorists] and to defend the nation and their country in the face of a global plot to stoke civil war [in the Arab country].”
Elsewhere in his remarks, the Leader said that 40 years of plots, threats and sanctions by the US and its stooges and mercenaries against the Iranian nation have failed.
Millions of black-clad pilgrims from across the world converge on the holy Iraqi city of Karbala every year to commemorate Arba’een.
Large groups of mourners, many of them Iranians, travel on foot toward the holy city to take part in the largest annual Islamic gathering on earth.
Arba’een, meaning “the fortieth” in Arabic, is observed 40 days after Ashura, the tenth day of the lunar calendar month of Muharram, when Imam Hussein was killed along with dozens of his companions at the hands of the tyrant of the time, Yazid I, more than thirteen centuries ago.
This year Arba’een falls on October 30.
Imam Hussein is a highly-venerated figure not only among Shia Muslims but also among Sunnis, Christians, and people of other faiths.