Iran's Supreme Leader Ayatollah Ali Khamenei on Tuesday accused the United States of trying to divide Iraq along sectarian and ethnic lines and urged Iraqis to withstand any such plans.

Shi'ite Muslim power Iran wields great influence in Iraq, which has a majority Shi'ite population. Its military advisers are helping direct Baghdad's campaign against Sunni Islamist militant group Islamic State, which seized around a third of Iraq's territory last year.

It was not clear if Khamenei was referring to a specific incident, but Iran has protested about US policy in Iraq several times this year.

"The Americans must not be allowed to consider Iraq as their personal property ... and dare to openly talk about disintegration of Iraq," Khamenei said according to his website.

"The Iraqi people, Shi'ites, Sunnis, Kurds and Arabs have been living together peacefully but some regional countries and some foreigners are trying to amplify differences among them," he added.

On Tuesday Khamenei met Iraq's President Fouad Massoum on the sidelines of the Gas Exporting Countries Forum (GECF) Summit in Tehran.

In August, outgoing US Army chief of staff General Ray Odierno drew condemnation from Baghdad and Tehran when he said reconciliation between Shi'ites and Sunnis in Iraq was becoming harder and that partitioning the country "might be the only solution."

In the instability resulting from the rise of Islamic State, Iraq's Kurds have expanded the reach of their autonomous regional government to include Kirkuk, which sits on substantial oil deposits.

The United States, whose 2003 invasion of Iraq marked the beginning of the country's descent into violence, is supporting Kurdish peshmerga fighting Islamic State and leads a coalition carrying out air strikes against the group. There are currently around 3,360 troops stationed in the country.

Iran's backing of Shi'ite militias fighting Islamic State has also added to sectarian divisions.

During a meeting with Russian President Vladimir Putin on Monday, Khamenei called for closer bilateral ties between Tehran and Moscow to thwart what he called "Washington's plots".-Reuters