Worried that Afghan peace talks are going nowhere, and facing a May 1 deadline for the possible withdrawal of all U.S. troops, the Biden administration has proposed sweeping plans for an interim power-sharing government between the Taliban and Afghan leaders, and stepped-up involvement by Afghanistan’s neighbors — including Iran — in the peace process.

Along with the proposal, shared with both sides over the past week by U.S. envoy Zalmay Khalilzad, Secretary of State Antony Blinken warned Afghan President Ashraf Ghani that a U.S. departure remains under active consideration and could lead to “rapid territorial gains” by the Taliban.

“I am making this clear to you so that you understand the urgency of my tone,” Blinken wrote in a three-page letter to Ghani sent to coincide with the proposal.

Biden administration officials refused to confirm or deny the specifics of the interim plan or the Blinken letter. “As a general matter, we do not comment on alleged correspondence with foreign leaders,” a State Department spokesperson said.

The letter and the eight-page plan for an interim government were published Sunday by Afghanistan’s Tolo News.

A senior administration official, speaking on the condition of anonymity about the sensitive diplomacy, declined to speak “to particular documents people have been discussing in the context of diplomatic conversations that should remain private.”

But “it’s important for both sides to understand the urgency of the situation, both the Afghan government and the Taliban,” the official said. “We inherited a diplomatic process and an agreement” and are trying “to resolve these outstanding issues.”

“Whether or not that’s possible is something that’s still being determined.”

The Afghan government had a blunt response to the leaked letter, stating that the United States cannot make decisions on behalf of the Afghan people.

Speaking at an event aired on local television Monday, Afghan First Vice President Amrullah Saleh said he is not “concerned about Blinken’s] letter” and it doesn’t change his administration’s position that only elected leadership can govern the country.

“We thank the U.S. for its support. They can make a decision on their troops, not on the people of Afghanistan,” Saleh said.

Ghani, who met with Khalilzad during a three-day visit to Kabul last week, on Saturday reiterated his opposition to any transfer of power except through elections but did not reject the interim notion outright.

Mohammad Naeem, the spokesman for the Taliban’s political office in Doha, said the group had received a copy of the plan “that the media is talking about.”

“It is under discussion [and] after discussion, we will have a position on it,” he said.

The Taliban has expanded its attacks on Afghan troops and territorial control, amid an increasing number of strikes against civilians.

Many Afghan experts say they believe the militants are moving closer to a military victory but are reluctant to again become a pariah government, losing all international support and aid for Afghanistan.

At the top of the U.S. list of outstanding issues is whether to bring home the remaining 2,500 U.S. troops in Afghanistan by May 1, a deadline set in an agreement signed by the Taliban and the Trump administration more than a year ago that led to rapid American downsizing.

The Pentagon has said that the Taliban has not complied with its commitments under the deal, including breaking its ties with al-Qaeda and reducing the level of violence. Start-and-stop Afghan-Taliban talks, called for in the agreement, began last September in Doha but have shown little progress.

The withdrawal decision is particularly difficult for President Biden, who opposed expansion of the U.S. presence in Afghanistan as vice president and, like President Donald Trump, pledged during his campaign to end “endless wars,” including the 20-year Afghan conflict. Staying could lead to political difficulties at home and renewed Taliban attacks on U.S. forces. Leaving could undermine any achievements made in the past two decades and lead to a Taliban takeover.

Domestic pressure and advice have come from lawmakers and interested parties on both sides of the decision.

“I would expect some extension” of the U.S. presence, Sen. Jack Reed (D-R.I.), the new chairman of the Senate Armed Services Committee, told reporters last month. He called a “pullout within several months” both “challenging” and “destabilizing.”

Others have called for Biden to quickly quit an unwinnable war. “Completely withdrawing our troops is sound policy, as American security interests do not require the continued presence of our troops in Afghanistan,” William Ruger, an Afghanistan veteran and fellow at the Washington-based Cato Institute, wrote in a recent opinion piece. Ruger’s nomination by Trump last fall as ambassador to Afghanistan expired when Trump left office.

Biden called for a review of Afghan policy, and Taliban compliance with the terms of the Trump deal, shortly after his inauguration.

“We have kept the president fully briefed on all the various aspects of our policy and deliberation,” the senior administration official said. “He’s asked questions; we’ve tried to give him information to answer those questions. He is the ultimate decision-maker. We are not at the point of presidential decisions.”

But there is a palpable sense of time running out within the administration. Asked what the administration will do if there is no peace agreement, the official declined to “prejudge or get ahead of decision-making or deal with hypotheticals.” But it is “one scenario among several that we’re going to have to plan for,” the official added.

In his letter to Ghani, Blinken requested the Afghan president’s “urgent leadership … in the coming weeks. … We have reached an initial conclusion that the best way to advance our shared interests is to do all we can to accelerate peace talks and to bring all parties into compliance with their commitments.”

In addition to the interim government proposal being shared by Khalilzad, Blinken wrote, “To move matters more fundamentally and quickly toward a settlement and a permanent and comprehensive cease-fire, we are immediately pursuing a high-level diplomatic effort,” including a request to the United Nations to convene a meeting among foreign ministers of regional countries and the United States.

Invitees, Blinken wrote, would include Russia, China, Pakistan, Iran and India. “It is my belief that these countries share an abiding common interest in a stable Afghanistan and must work together if we are to succeed,” he said.

Blinken also said the United States would ask Turkey to host a senior-level meeting between the Taliban and the Afghan government “in the coming weeks.” He encouraged Ghani, who is seen by Washington as recalcitrant, and whose government is beset by domestic rivals, to broaden his consultations with an “inclusive” group of Afghans.

Turkey maintains a noncombat force in Afghanistan as part of the NATO-led coalition that has about 10,000 troops, far exceeding the U.S. presence. The administration has said it is fully consulting with NATO and other partners.

The United States, Blinken wrote, has prepared “a revised proposal for a 90-day Reduction in Violence, which is intended to prevent a Spring Offensive by the Taliban” and to coincide with diplomatic peace efforts.

“I must also make clear to you, Mr. President, that as our policy process continues in Washington, the United States has not ruled out any option,” Blinken said, among them “the full withdrawal of our forces by May 1st.”

The proposal published by Tolo News, dated Feb. 28, has a number of bracketed items, including the “[xx] months” an interim government would be in place. Under a section titled “Guiding Principles,” it states that Islam will be Afghanistan’s official religion, with a new High Council of Islamic Jurisprudence to provide guidance to all levels of government, although an independent judiciary would have the last word.

It calls for protection of women’s rights and strengthening of institutions, support for conflict victims and “a national policy of transitional justice … that focuses on truth-seeking, reconciliation, healing and forgiveness.”

The “transitional Peace Government of Afghanistan,” it says, shall include separate but coequal executive, parliamentary and judicial branches, adhering to the current 2004 constitution until it can be revised.

The proposal offers two options for the executive — a president and an unspecified number of vice presidents, or a president and a prime minister. Leaders under a presidential system are to be selected by agreement between the two parties and “acceptable to both sides.” The interim president and vice presidents would be prohibited from serving in those roles in any future government.

The president would serve as commander in chief, establishing a joint board to integrate military forces and adjust the chain of command.The existing parliament would either be suspended, with legislative authority transferred to the executive, or new members in a bicameral legislature would be chosen under a complicated division between the two sides.The interim president would appoint provincial governors, who would appoint mayors and district leaders. Under two options, provincial councils would be suspended, with authority reverting to governors, or membership would be expanded, with the Taliban appointing some new members in unspecified provinces.Each side would choose an equal number of Supreme Court justices, with the president given an extra choice. Elections would be held under the new constitution, administered by an Afghan election commission or an international supervisory body.

Once a peace agreement is signed, “each side shall immediately announce and implement [within xx hours] an end to all military and offensive operations and hostile activities against the other,” the proposal says. A joint commission from each side, with three independent international observers, would provide written rules and monitoring.

Susannah George contributed to this report.