UNITED NATIONS (AP) — The United States and several Western allies on Tuesday accused the Syrian government of deliberately delaying the drafting of a new constitution to waste time until presidential elections in 2021, and avoid U.N.-supervised voting as called for by the U.N. Security Council.

U.S. deputy ambassador Richard Mills urged the Security Council to “do everything in its power” to prevent Bashar Assad’s government from blocking agreement on a new constitution in 2020. The Trump administration believes Assad's hope is to “invalidate the work” of U.N. special envoy Geir Pedersen who has been trying to spearhead action on a constitution, and the council's call for a political transition.

The Security Council resolution adopted in December 2015 unanimously endorsed a road map to peace in Syria that was approved in Geneva on June 30, 2012 by representatives of the United Nations, Arab League, European Union, Turkey and all five permanent Security Council members — the U.S., Russia, China, France and Britain.

It calls for a Syrian-led political process starting with the establishment of a transitional governing body, followed by the drafting of a new constitution and ending with U.N.-supervised elections. The resolution says the free and fair elections should meet “the highest international standards” of transparency and accountability, with all Syrians — including members of the diaspora — eligible to participate.

At a Russian-hosted Syrian peace conference in January 2018, an agreement was reached to form a 150-member committee to draft a new constitution. That took until September 2019, and since then only three meetings have been held with little progress.

Pedersen, the U.N. envoy, told the Security Council Tuesday he was unable to convene a fourth meeting in October because the government wouldn’t accept a compromise agenda which the opposition agreed to. During his just concluded visit to Damascus, he said there was “some valuable narrowing of the differences” that could enable consensus on agendas for the next two meetings.

“If we are able to find agreement in the next two days, it should be possible to meet in Geneva sometime in the month of November,” Pedersen said, dropping the Nov. 23 date in his prepared speech.

Mills, the U.S. envoy, urged Pedersen “to take any measures he thinks are appropriate to facilitate the parties’ efforts ... and also to identify to the council who is blocking progress.”

“Syria is wholly unprepared to carry out elections in a free, fair and transparent manner that would include the participation of the Syrian diaspora,” Mills said. “This is why we need the constitutional committee to work, and why we need the U.N. to accelerate its planning to ensure Syria’s upcoming elections are credible.”

German Ambassador Christoph Heusgen called Assad’s “delaying and obstruction tactics” on the constitutional committee’s work “just detestable.”

He said Russia, Syria’s most important ally, “should finally use its influence by, for instance, just cutting military aid and stopping its support, so that the Syrian regime finally plays ball.”

Syria's tactics are clear, Heusgen said. “They want to waste time until the presidential elections in 2021. The regime should not have any illusions. The elections will not be recognized if they are held under the present circumstances.”

French Ambassador Nicolas De Riviere also criticized Assad’s “refusal to engage in good faith” and called for preparations to begin for U.N.-supervised elections that include the diaspora. France won’t recognize results that don’t comply with these provisions, he said, stressing: “We will not be fooled by the regime’s attempts to legitimize itself.”

Russia’s ambassador, Vassily Nebenzia, made no mention of the April presidential election and countered that Syrians must have “the opportunity to negotiate without interference from the outside.”

“The work of the constitutional committee should not be subject to any deadlines,” he said, expressing hope that Pedersen’s mediation will enable the committee’s work to continue “in line with the agenda agreed by the Syrians.”

Russia also sparred with Western ambassadors over its veto threats that led to the closure of two border crossings to deliver aid to Syria -- one in the northeast and one in the northwest -- leaving only one crossing to Idlib in the northwest.

The U.S., Germany, France, Britain, Belgium and others criticized the border crossing closures.

U.N. humanitarian chief Mark Lowcock told the council that Syrian government deliveries across conflict lines to the northeast are “not delivering at the scale or frequency required to meet the current health needs.” He said one hospital received only 450 gowns in April, and another received nothing for its maternity wing.

Lowcock also said “the situation of families across Syria is truly desperate,” citing food prices more than 90 percent higher than six months ago.

Russia’s Nebenzia responded, noting “with satisfaction the progress in U.N. humanitarian deliveries from inside Syria including through cross-line routes,” saying this “proves” the government is providing aid to people including in areas not under its control.