Mahmoud Ahmadinejad, the Iranian president, told ministers from Iraq's neighbours that surrounding states were committed to ensuring stability in Iraq.
"It is necessary to stop the crossing of terrorist groups into Iraq who aim at creating insecurity, hatred and differences, and pave the way for the presence of foreign forces in Iraq," Ahmadinejad told the foreign ministers in Tehran on Saturday.
He did not say where "terrorist" groups were crossing into Iraq from or how they were entering.
The US accuses Iran of backing some insurgent groups in Iraq, a charge which Tehran denies.
"We are all committed to try to restore stability, security and progress in Iraq," Ahmadinejad said.
Manouchehr Mottaki, the Iranian foreign minister, called for a timetable to be drawn up for the withdrawal of foreign forces and said Iraq's neighbours should not be blamed for the country's problems.
Syria has also been accused by Washington of not doing enough to stop militants crossing into Iraq. When asked what more Damascus could do to secure its border, Walid al-Moualem, the Syrian foreign minister, said: "We are doing our best."
Iraq's neighbours fear instability
in the region
Iraq blames much of the insurgency on foreign fighters and has urged its neighbours to improve security on its borders. Neighbouring countries have expressed concern that the current instability in Iraq could pose a security threat to the whole region.
Hoshiyar Zebari, the Iraqi foreign minister, said he wanted neighbouring states to help improve security, support the new government of Nuri al-Maliki and the national reconciliation plan.
"We asked them to use their influence over all the groups to participate, to embrace this national reconciliation initiative," Zebari told reporters.
Iraqi officials have said some insurgents have asked Arab states to act as mediators following the offer of dialogue with the groups.
Officials from Iraq, Saudi Arabia, Kuwait and Turkey – who share borders with Iraq - were among those at the meeting, along with Egypt and Bahrain.