Relations between the Trump administration and the government of Afghanistan fell to a new low this week, as they exchanged public accusations of bad faith and exposed deep differences over U.S. negotiations with the Taliban.

On a visit to Washington, Afghanistan’s national security adviser, Hamidullah Mohib, charged that any U.S. deal with the Taliban would “dishonor” American troops who have fought and died in the war. Afghan-born U.S. negotiator Zalmay Khalilzad was acting out of “personal ambition,” Mohib said, and seeking to “create a caretaker government, of which he will become viceroy.”

In Kabul, U.S. Ambassador John R. Bass responded Thursday on Twitter that it was “Afghan corruption and misuse of equipment, funds and other support provided by the American people” that dishonored the troops. “So do any Afghans who put their personal or political interests ahead of the national interest,” Bass tweeted.

In a sharply worded statement, the State Department said Mohib had been “summoned” to a meeting with U.S. Under Secretary for Political Affairs David Hale, who reminded him that “attacks on Ambassador Khalilzad are attacks on the Department and only serve to hinder the bilateral relationship and the peace process.”

President Trump has said he wants to withdraw all 14,000 U.S. troops from Afghanistan, a vow that his top military and civilian aides recently persuaded him to tie to progress in the Taliban negotiations.

The Afghan government has been excluded from talks between Khalilzad and Taliban representatives, who concluded a lengthy fifth round of negotiations Tuesday in Qatar. Afghan-to-Afghan talks about the country’s future eventually will happen, Khalilzad has said, but the dialogue has focused so far on U.S. counterterrorism concerns and the Taliban demand for foreign troops to withdraw.

The U.S.-Afghan relationship has been marked by mutual suspicion and exasperation throughout the nearly 18 years since the Afghan war began, when U.S. troops arrived and ousted the Taliban government. But, with the exception of a brief foray under President Barack Obama, successive U.S. administrations have rebuffed repeated Taliban demands to hold direct talks with Washington, saying they should be talking to their own government. The Taliban calls the Kabul government a U.S. “puppet.”

During his campaign, Trump described the Afghan war as a “total disaster” and vowed to bring home U.S. forces. Instead, a lengthy White House review of Afghanistan policy resulted in the deployment of 5,000 additional troops and a commitment to a “conditions-based” withdrawal with no timetable.

By most measures, Taliban control of Afghan territory has increased since then. In the summer, the administration announced the appointment of Khalilzad, a former U.S. ambassador to both Afghanistan and Iraq during the George W. Bush administration, as Trump’s special adviser on Afghanistan.

His “singular mission,” Secretary of State Mike Pompeo said at the time, will be “developing the opportunities to get the Afghans and the Taliban to come to a reconciliation.”

Direct U.S. talks with the Taliban began soon afterward. After the fourth round in January, Khalilzad announced an agreement in principle on a draft “framework” for the eventual full withdrawal of U.S. forces, and a Taliban guarantee that Afghan territory would never be used by terrorists — including al-Qaeda and the Islamic State.

Trump indicated a week later, in his State of the Union address, that there was no date for withdrawal. But “as we make progress in these negotiations,” he said, “we will be able to reduce our troops’ presence and focus on counterterrorism.”

President Ashraf Ghani’s government, already livid from what it said was a failure by a “disrespectful” Khalilzad to even provide them with a comprehensive briefing on the talks, hit the roof, placing most of the blame on Khalilzad.

“The last people to find out is us,” Mohib said in a briefing for reporters Thursday. “We get bits and pieces of information,” he said, charging that Khalilzad’s report to Ghani after the January talks “was about six minutes.”

“In the space of information and reconciliation, there is no transparency . . . and a hell of a lot of tension,” he said. “We are told that Zal,” as Khalilzad is widely known, “is a great diplomat. I’m not sure I buy that. He is ostracizing and alienating a very trusted ally. . . . We think either Zal doesn’t know how to negotiate, or there are other reasons behind” his actions.

Asked what those reasons were, Mohib said Khalilzad had twice before expressed interest in running for president of Afghanistan and has numerous friends and contacts among Ghani’s political opponents.

As it directs its ire toward Khalilzad, Ghani’s government seemed to be trying to avoid blaming Trump.

When Vice President Pence visited Afghanistan four days before Christmas, Mohib said, he told Ghani that Trump was “not looking to withdraw” but was “looking for peace.” Trump flew in five days later to visit U.S. troops but met with no Afghan officials.

“Try to reassure us,” Mohib said, appealing to the White House. “Tell us what the president’s policy is. . . . We are asking for our sovereign rights,” he said, and “don’t need colonialist approaches.”

Ghani has asserted repeatedly that any credible peace negotiations must include Afghan authorities and a cross section of society, and he has announced that a national assembly will be held next month on the issue.

But with presidential elections scheduled for July, Ghani has faced instability within his administration, as well as political competition and in some cases violent defiance from longtime partisan and ethnic rivals.

Writing Tuesday on Twitter, at the end of the most recent round of talks, Khalilzad declared, “The conditions for #peace have improved. It’s clear all sides want to end the war. Despite ups and downs, we kept things on track and made real strides.”

As soon as a draft agreement on foreign troop withdrawal and counterterrorism measures is finalized, he said, “the Taliban and other #Afghans, including the government, will begin intra-Afghan negotiations on a political settlement and comprehensive cease-fire.”

In Senate testimony Tuesday, Gen. Joseph F. Dunford Jr., chairman of the Joint Chiefs of Staff, and acting defense secretary Patrick Shanahan expressed support for the talks, which Shanahan called “the best window for peace there in 40 years.”

Pamela Constable in Kabul and Paul Sonne in Washington contributed to this report.