Taliban commanders are under specific orders to step up their attacks on American troops, Fox News senior strategic analyst Gen. Jack Keane said Monday in response to an attack that killed two U.S. soldiers in Afghanistan over the weekend.

“Ever since the negotiations were broken off as a result of a killing of a U.S. soldier at the time when President Trump terminated those negotiations a number of months ago, the tactical commanders received orders to do everything they possibly can to increase the casualties to Americans,” Keane told “America’s Newsroom.”

AFGHANISTAN 'INSIDER ATTACK' LEAVES 2 US SOLDIERS DEAD, 6 WOUNDED

"This is designed principally to break American will at home to suggest that the war is futile, and therefore, we should just walk away.”

Keane’s comments came after two U.S. soldiers were killed and six were wounded Saturday when American and Afghan troops were fired on during a mission in Nangarhar province in eastern Afghanistan, U.S. officials told Fox News.

The casualties occurred when an Afghan wearing an army uniform suddenly opened fire, The Associated Press reported.

The U.S. military has not officially called the incident an "insider attack" because the motive remains unclear, and the shooter “was not one of the soldiers on the patrol,” a U.S. defense official told Fox News.

Such attacks have been frequent in the nearly two decades U.S. troops have been deployed in the country. In 2012, for example, 25 percent of American military deaths in Afghanistan were caused by allied Afghan forces, military officials have said.

Since Jan.1, six U.S. service members have been killed in Afghanistan, including the two soldiers killed Saturday. Last year, 22 U.S. service members were killed in action there.

In September, President Trump abruptly canceled talks with the Taliban, including a visit to Camp David, after an American soldier was killed in the country. The attack Saturday comes months after Trump made a surprise visit to Afghanistan on Thanksgiving to announce he has resumed negotiations with the Taliban.

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The Trump administration is weighing a decision to remove up to 4,000 U.S. troops from Afghanistan.

There are currently about 12,000 US troops deployed there. Keane said the deployment of American soldiers to Afghanistan remains in the "vital national interest" and that our men and women in uniform have served for 18 years there to make sure the country does not again turn into a base for terrorists.

Fox News’ Nick Givas contributed to this report.