Iraqi President Jalal Talabani, a Kurd, met with Iranian Quds Force Commander Brig. Gen. Qassem Soleimani following clashes with Iraqi forces and Shiite militants in Basra. Talabani left the meeting with a message from Soleimani saying he "was deeply concerned" and "promised to stop arming groups in Iraq and to ensure that groups halt activities against U.S. forces," The Christian Science Monitor reported Wednesday.

Talabani told top U.S. officials following the meeting that this "was an entirely different tone than we had ever heard from (Soleimani) before," and advised them to "please take it seriously," unnamed sources told the Monitor.

U.S. officials repeatedly blame Iran for backing so-called special groups in Iraq and for meddling in Iraqi affairs. In late April, however, a delegation of officials hand-picked by Iraqi Prime Minister Nouri al-Maliki returned from a meeting in Iran with pledges of support for Iraqi efforts to rein in the militants.

Haidar Abbadi with Maliki's Dawa Party said Iranian officials were "committed to acting more positively" and referred to the Monday truce signing as a "good sign" the Iranians were keeping to their word, the newspaper said.