KABUL — In a sign of mounting frustration with Afghanistan's leaders, Secretary of State Mike Pompeo announced early Tuesday that the United States would cut $1 billion in aid to the country because of its inability to form a unity government to negotiate with the Taliban.

Pompeo said that Afghan President Ashraf Ghani and his main rival, Abdullah Abdullah, had failed to set aside their differences, just hours after meeting with the two men in a quickly arranged visit to Kabul.

"The United States is disappointed in them and what their conduct means for Afghanistan and our shared interests," Pompeo said in a statement. "Their failure has harmed U.S.-Afghan relations and, sadly, dishonors those Afghan, Americans, and Coalition partners who have sacrificed their lives and treasure in the struggle to build a new future for this country."

For weeks, the Trump administration has been pressuring the Afghan government to put together a united team to negotiate with the Taliban and form a lasting peace deal in Afghanistan that allows for the withdrawal of U.S. forces.

Pompeo's statement reflects the Trump administration's willingness to condition aid to Afghanistan in order to force the compliance of Ghani and Abdullah.

"We are prepared to reduce by another $1 billion in 2021," Pompeo said, emphasizing that the two leaders' intransigence would not delay America's withdrawal plans.

"We are proceeding with the conditions-based withdrawal of our forces in accordance with the U.S.-Taliban agreement," he added.

After leaving Afghanistan, Pompeo met with the Taliban's chief negotiator in Qatar. Following those discussions, he told reporters that the Trump administration's principal concern right now is the Afghan leadership, not the Taliban.

"They committed to reducing ­violence and they've largely done that," Pompeo said, referring to the Taliban.

He added that he hoped the United States wouldn't need to withhold aid from Afghanistan.

"We are hopeful, frankly, that they will get their act together and we won't have to do it. But we're prepared to do that," Pompeo said.

Pompeo arrived in Kabul on Monday in hopes of resolving a clash between Ghani and Abdullah, who is attempting to form a parallel government. Pompeo spent the day meeting privately with both leaders, first separately and then together, before leaving the country less than nine hours after he landed.

The secretary's sudden trip from Washington, even with the novel coronavirus upending life in the United States and consuming its government, was a dramatic indicator of U.S. officials' growing alarm at the lengthening political stalemate here — both for its potential to erupt into a violent civil conflict and to undermine the peace process.

The peace agreement signed Feb. 29 between U.S. and Taliban officials was expected to allow thousands of U.S. troops to begin leaving Afghanistan soon and to pave the way for negotiations between Taliban and Afghan leaders on a shared government in the future. Instead, both plans have bogged down, and no date has been set for the talks.

"Unless this crisis gets resolved and resolved soon, it could affect the peace process, which was an opportunity to end . . . 40 years of war. And our agreement with the Talibs could be put at risk," a senior State Department official told journalists traveling with Pompeo, speaking on the condition of anonymity to be candid.

The official said Pompeo's "authority" as the top U.S. diplomat and a close adviser to President Trump gives him more potential influence than other intermediaries on Ghani and Abdullah, who are bitterly estranged after co-governing for five years. In recent weeks, both Zalmay Khalilzad, the U.S. diplomat spearheading the peace talks, and senior Afghan political and religious leaders have tried to find a compromise — to no avail.

Even with "a lot going on," including the coronavirus pandemic, the official said, Pompeo had "come all the way here" to "push" both Afghan leaders to form an inclusive government and to stress the dangers that could result "if they don't do the right thing." The official said there was particular concern that the Afghan defense forces could split between "two presidents and two commanders in chief, or worse."

What the Trump administration wants is for Ghani and Abdullah to agree on an "inclusive government that is acceptable to both," the official said. "We are encouraging them to rise to the occasion" and "put the country first."

After back-to-back meetings, with Pompeo shuttling between Ghani's and Abdullah's palaces — one block apart — and then meeting with them together, no official statements were made.

Pompeo then flew to Qatar, where he met with the Taliban's chief negotiator, Abdul Ghani Baradar. The two men spoke for about an hour at Al Udeid Air Base in Doha, where Pompeo pressed the Taliban "to continue to comply with the agreement signed last month," said State Department spokeswoman Morgan Ortagus.

The political crisis arose after the presidential election in September. Ghani, the incumbent, was declared the winner last month, but Abdullah alleged massive fraud and refused to concede. The two have been locked in a tense stalemate for two weeks, while Abdullah, backed by an array of former ethnic-minority militia leaders, has begun naming his own governors and cabinet members.

Meanwhile, no progress has been made on forming a government delegation to meet with the Taliban, even though those talks were scheduled to begin March 10. In a separate dispute, Ghani has refused to immediately release 5,000 Taliban prisoners as the U.S.-Taliban agreement stipulated, throwing that deal into doubt as well, and leaving unclear if and when American troops can begin pulling out in large numbers.

Pompeo's mission is eerily reminiscent of what transpired after the previous Afghan presidential election, in 2014, when then-Secretary of State John F. Kerry successfully mediated an identical spat between Ghani and Abdullah. Both claimed to have won the presidency in a fraud-marred election, but Kerry persuaded them to accept a power-sharing arrangement. It has proved tense and fractious.

Pompeo, who attended the signing of the peace agreement in Qatar, said at the time that the path forward would be “rocky” and that talks between Taliban and Afghan leaders would be difficult. But he also said that while Taliban leaders have “an enormous amount of blood on their hands, they have now made a break” with their past and promised not to allow anti-U.S. terrorist activities on Afghan soil.

Hudson reported from Washington.