The U.S. Ambassador to Iraq Ryan Crocker on Tuesday accused Iran of stepping up its support for Iraqi militias after the first round of U.S.-Iran talks in May.
"Over the roughly two months we have actually seen militia- related activities that can be attributed to Iranian support go up and not down," Crocker said after his second meeting with his Iranian counterpart Hassan Kazemi-Qomi in the heavily fortified Green Zone.
So far, there was no response from the Iranian delegation.
The second round of landmark U.S.-Iran talks began at about 10: 00 a.m. (0600 GMT), with a speech made by the Iraqi Prime Minister Nuri al-Maliki who welcomed the talks of the two arch rivals over the Iraqi security issue.
Several Iraqi officials, including Maliki and Foreign Minister Hoshyar Zebari, attended the meeting.
The two ambassadors made their first round of talks on May 28 in Baghdad in an effort to find solutions for Iraqi security problems. However, their first meeting ended without substantial achievements.
U.S. forces accuse Iran of arming and training Iraqi militias to fight with U.S. troops, allegations Iranian officials have denied. Iran authorities call for an immediate withdrawal of U.S. troops to stabilize Iraq.