President Joe Biden is testing whether he can bring sweeping changes in Afghanistan, including a potential government involving the Taliban, in a high-risk strategy as he weighs whether to honor a May deadline to end America’s longest war.

In a letter leaked to Afghan media over the weekend, Secretary of State Antony Blinken encouraged Afghan leaders to consider a “new, inclusive government” and proposed that talks take place within weeks in Turkey to seal a peace deal with the Taliban.

The behind-the-scenes but dramatic diplomacy comes as Biden completes a review on one of his first major foreign policy questions — whether to abide by an agreement with the Islamist insurgents negotiated by former president Donald Trump to pull the final US troops out by May.

“I think the objective here seems to be, let’s see if there’s some other option that we have other than simply leaving on May 1 or overstaying. Is there some short-cut to a peace process?” said Laurel Miller, the former US envoy on Afghanistan and Pakistan.

“I see this as just trying stuff and looking to see if something sticks,” said Miller, Asia director at the International Crisis Group.

In the letter to President Ashraf Ghani reprinted by Afghanistan’s TOLOnews, Blinken said with uncharacteristic bluntness that the United States feared the “security situation will worsen and the Taliban could make rapid territorial gains” if the United States ends its two-decade military involvement.

While saying the United States did not want to dictate terms, Blinken encouraged Ghani to “move urgently” on ideas from Zalmay Khalilzad, the veteran US negotiator kept on from the Trump administration.

Blinken proposed a 90-day reduction in violence that would avoid the Taliban’s bloody annual spring offensive.

In addition to the meeting in Turkey, Blinken said the United States was asking the United Nations to convene a meeting of foreign ministers from Afghanistan’s neighbors on ensuring future stability that would notably include Iran — in what could turn out to be a first diplomatic encounter with the Biden administration.

Afghan Vice President Amrullah Saleh denounced the ideas in the letter, saying that the Taliban could enter elections but that the country’s fate would not be decided by “20 people in a room.”

“We thank the US for their support. They have the right to decide on their 2,500 troops,” he told an event in Kabul. “We also have the right to decide on the fate our 35 million people.”

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“We will never compromise our dignity. Our dependency on the outside world does not mean we obey illegitimate demands,” Saleh said.

The State Department did not confirm or deny the letter, saying it would not discuss Blinken’s correspondence.

But State Department spokesman Ned Price said the administration was pursuing diplomacy aimed at permanently ending the fighting and bringing a political solution.

“We have continued to encourage all sides to take part constructively, and with a degree of alacrity, knowing that this is a moment in time where progress is possible,” Price told reporters.

Biden as vice president was an early proponent of limiting involvement in Afghanistan, seeing little further scope for progress — a rare point of agreement with Trump who vowed to end “forever wars.”

But Biden has since spoken of keeping a limited force to strike extremists — an idea likely to draw opposition from the Taliban, who have held fire against US-led coalition troops but have kept up their violence against the government.

First Lady Jill Biden also promised Monday that the president will factor in women, who faced extreme restrictions under Taliban rule, telling an event: “The United States will stand with you.”

Scott Warden, director of the Afghanistan and Central Asia programs at the US Institute of Peace, said it was unrealistic to come up with an entirely new governing framework by May — but that Blinken’s letter could make clear what is possible.

“The bottom line is, if this letter can get people’s attention and actually moves to discussion of the key terms,” he said, “then you can consider it progress.”

Biden officials “really don’t want to let the May 1 deadline drift or expire without making every effort that they can to get a constructive peace process going.”

Miller, the former envoy, saw risks in the approach if the Biden administration is indeed set on leaving Afghanistan.

“Don’t dismantle the Afghan government on your way out the door. You’re not going to get a quickie peace settlement that’s going to solve it all and bring the Taliban in over the next seven weeks,” she said.

“So if you’re intent on leaving, at least leave something that can have some modest potential to stand on its own.”