The United States is ready to hold new direct talks with Iran on the deteriorating security situation in Iraq, the State Department said Tuesday. The Bush administration accused Tehran of supporting Shia insurgents there.

"We think that given the situation in Iraq and given Iran's continued behavior that is leading to further instability in Iraq, that it would be appropriate to have another face-to-face meeting to directly convey to the Iranian authorities that if they wish to see a more stable, secure, peaceful Iraq, which is what they have said they would like to see, that they need to change their behavior," spokesman Sean McCormack told reporters.

"They need to stop supporting sectarian militias that are exacerbating sectarian tensions, they need to stop supporting EFP networks that pose a threat to our troops," he said, referring to Explosively Formed Penetrators, devices crafted to penetrate armored vehicles that Washington claims are being sent to insurgents by Iran.

"It is important to directly convey to the Iranian government the importance of their changing their behavior, not only for the safety of our troops, but also for the future of Iraq," McCormack said.

He said a date for the talks had yet to be arranged but suggested that discussions were under way on setting a time for the meeting, which would be the first between the two arch-foes since late May when U.S. ambassador to Iraq, Ryan Crocker, met Iranian officials in Baghdad.

That May 28 meeting marked a break in a 27-year diplomatic freeze and was expected to have been followed within a month by a second encounter. But since then, bitterness has mounted as U.S. officials have stepped up allegations of Iranian involvement in the Iraq insurgency.

Tensions have also risen over Tehran's detention of four Iranian-American scholars and activists charged with endangering national security. The U.S. has demanded their release, saying the charges against them are false.

At the same time, Iran has called for the release of five Iranians detained in Iraq, whom the United States has said are the operations chief and other members of Iran s elite Quds Force, which is accused of arming and training Iraqi militants. Iran says the five are diplomats in Iraq with permission of the government.

Until Tuesday the United States had resisted another round of talks despite entreaties from the Iraqi government and Iranian hints at their willingness to sit down.

Earlier Tuesday, Iranian Foreign Minister Manouchehr Mottaki said Iran was willing to hold a second round of talks with the United States over stabilizing Iraq in the near future if Washington officially asks for one.

"We look positively at holding a second round of talks. There exists a possibility to hold such talks in the near future," Mottaki told a news conference in Tehran. However, he said the U.S. had not yet made such a request through official channels.

The Iraqi government, which is backed by the U.S. but closely allied to Iran, has been trying to get the two sides together, hoping some cooperation will reduce violence in the wartorn country.