UNITED NATIONS, United states -- Secretary of State Antony Blinken on Tuesday warned Iran that the United States would respond "decisively" to any attack by its proxies, as tensions rise with the Israel-Hamas war.

"The United States does not seek conflict with Iran. We do not want this war to widen. But if Iran or its proxies attack US personnel anywhere, make no mistake. We will defend our people, we will defend our security -- swiftly and decisively," Blinken told a UN Security Council session.

The United States has accused Iran of assisting a renewal of attacks on US forces based in Iraq as part of a coalition against the Islamic State group.

Iran's clerical leadership supports Hamas, which carried out a bloody assault on October 7 inside Israel which has responded with massive retaliation. Iran also has a close relationship with Lebanon's Shiite militia Hezbollah which has had repeated conflicts with Israel.

The United States, the top diplomatic backer of Israel, last week vetoed a draft resolution on the conflict, saying it should have explicitly defended Israel's right to self-defense.

The United States has put forward a new resolution seen by AFP that would voice sympathy for both Israeli and Palestinian casualties and defend "the inherent right of all states to individual and collective self-defense" while complying with obligations under international law.

The new resolution "incorporates substantive feedback that we received from fellow Council members over recent days," Blinken said.

Sharing graphic accounts of Hamas militants killing children and other civilians, Blinken asked, "Where's the outrage? Where's the revulsion? Where's the rejection? Where's the explicit condemnation of these horrors?"

"We must affirm the right of any nation to defend itself and to prevent such harm from repeating itself. No member of this Council --  no nation in this entire body -- could or would tolerate the slaughter of its people," Blinken said.