Powerful Shiite cleric Moqtada al-Sadr Wednesday voiced opposition to US military advisers who have begun meeting with Iraqi commanders, and warned that his supporters would "shake the ground" in combatting militants.

"We will shake the ground under the feet of ignorance and extremism," he said, referring to Sunni insurgents who have overrun a swathe of territory in the past two weeks, in a televised speech from the Shiite holy city of Najaf.

He added that he only supported "providing international support from non-occupying states for the army of Iraq".

The cleric's remarks came days after fighters loyal to him paraded with weapons in the Sadr City area of north Baghdad, vowing to fight a major militant offensive that has alarmed the world and threatens to tear Iraq apart.

Iraq's flagging security forces, which were swept aside by the initial offensive but have since at least somewhat recovered, have already been joined by some Shiite fighters, and thousands more are ready to take part.

Sadr's Mahdi Army militia, which battled US forces for years when American troops were stationed in Iraq during their country's nearly nine-year war, remains officially inactive, but fighters loyal to the cleric have nevertheless vowed to combat the militant advance.

Kerry to visit Saudi Arabia on Friday for Iraq talks
Brussels (AFP) June 25, 2014 - US Secretary of State John Kerry will travel to Saudi Arabia on Friday for talks with King Abdullah about the crisis in Iraq.

Speaking on the sidelines of talks at NATO, Kerry announced the extra stop on his current whirlwind tour saying he would stress "the great urgency" of the conflict in Iraq and brief Saudi leaders on his visits to Baghdad and Arbil this week.

"President Obama has also asked me travel to Saudi Arabia on Friday in order to meet with his majesty King Abdullah to discuss regional issues, including clearly the situation in Iraq," Kerry told a press conference Wednesday.

The two men would also talk about "how we can counter the sheer threat that is posed by ISIL as well as to discuss our support for the moderate opposition in Syria."

"None of us need to be reminded that a far away threat can have tragic consequences at home in the most unexpected way, the most unexpected moment," Kerry added.

Sunni Militants, spearheaded by the jihadist Islamic State of Iraq and the Levant (ISIL) and joined by supporters of executed dictator Saddam Hussein, have overrun a large chunk of northern and north-central Iraq in the past week, although their advance has since been slowed.

Saudi officials have said the "sectarian" policies of Baghdad's Shiite-led government are to blame for the takeover by Sunni insurgents of key cities and large swathes of the country.

Saudi media have played down the role of ISIL, designated by the Sunni-dominated kingdom as a "terrorist" organisation, and highlighted the role of Sunni tribes and other armed groups in the insurgency.

UN triples appeal for aid funding in Iraq
United Nations, United States (AFP) June 25, 2014 - The United Nations has tripled its appeal for humanitarian funding for Iraq in 2014 to more than $312 million, with the country battling a fierce militant onslaught.

A lightning offensive by Sunni militants in recent weeks has overrun swaths of five Iraqi provinces, killed nearly 1,100 people and displaced hundreds of thousands.

"The funding is urgently needed to help one million people affected by the conflict, including in Mosul and Anbar," said Wednesday Stephane Dujarric, spokesman for UN Secretary General Ban Ki-moon.

But he cautioned that the original $103 million appeal was "one of the least-funded appeals for 2014, with only six percent of the funding" received so far.

Speaking to journalists via video conference from Baghdad, UN special envoy for Iraq, Nikolay Mladenov, emphasized that in the country "over one million people have been displaced since January."

He said that among those who have fled their homes, some "are increasingly facing challenges in getting food, many of them dropping to one meal a day.

"The situation remains dire, our resources are overly stretched since the beginning of the year."