BAGHDAD (Reuters) -- Iraq and Iran are seriously at odds on defining their land and sea borders, Baghdad's foreign minister has said in comments that showed the neighbors, despite improved ties, have not resolved old tensions.
"We have very big problems with the Iranian side with setting and drawing the land, sea, and coastal borders," the minister, Hoshiyar Zebari, told Iraqi television station Al-Sharqiyah.
"We also have problems with the Shatt Al-Arab channel. Our longtime attempts to convince Iran about the necessity and the importance of moving forward together, in order to avoid problems, have been frustrated," he said.
A dispute over the two countries' border and over control of the strategic Shatt al-Arab waterway, known in Iran as Arvand Rud, helped trigger the Iran-Iraq war, which killed an estimated 1 million people from 1980 to 1988.
Shatt Al-Arab, which joins the Tigris and Euphrates rivers and empties into the Gulf below Iraq's port city of Al-Basrah, is Iraq's only shipping outlet.
Ties between the two Shi'ite-led countries improved after the fall of Sunni Arab ruler Saddam Hussein in the U.S.-led invasion of Iraq in 2003. But there are numerous strains, many of them rooted in the presence of U.S. troops and their support for the government of Prime Minister Nuri al-Maliki.
There have also been suggestions from within the Iraqi government that Iraq wants to renegotiate a 1975 border treaty, an idea that has been rejected by Iran.
The two countries share deep historic and religious ties, and millions of Iranians visit Muslim holy sites in Iraq each year. Many members of al-Maliki's coalition government have close ties to Iran.