US State Department spokeswoman Tammy Bruce claimed in a statement on Monday that the conference was "useless and ill-timed."
"The United Nations is hosting a futile and ill-timed conference on the two-state solution this week," she said. "The conference, far from promoting peace, will prolong the war, embolden Hamas, and undermine realistic efforts to achieve peace."
Bruce confirmed that the United States did not participate in the conference, adding, "Our focus is on serious diplomacy, not on conferences held to show that they are important."
The spokeswoman also criticized France's decision to recognize the State of Palestine, noting that it "satisfied Hamas," and affirmed Washington's rejection of the decision.
Earlier on Monday, the ministerial conference kicked off at the United Nations headquarters, co-chaired by Saudi Arabia and France and attended by high-level participants. The conference discussed ways to implement the two-state solution and support the process of international recognition of the Palestinian state.
The International Palestine Conference was scheduled to be held at the United Nations headquarters in New York from June 17 to 20. However, following the Israeli attacks on Iran, which began on June 13 with US support and lasted for 12 days, French President Emmanuel Macron announced the postponement of the conference.
With US support, Israel is waging a war of extermination in Gaza, including killing, starvation, destruction, and forced displacement, ignoring all international calls and orders from the International Court of Justice to halt the operation.
The US-backed genocide left more than 205,000 Palestinians dead or wounded, most of them children and women, and more than 9,000 missing, in addition to hundreds of thousands of displaced persons and a famine that claimed the lives of many.