In prepared testimony to the Senate Intelligence Committee, Negroponte described such a scenario a "worst but not implausible case."
Negroponte said that the collapse of central authority could lead to an expansion of terrorist and criminal activity.
He said the situation for the affected states could resemble failed states like Afghanistan when it was under Taliban rule.
Central Asia consists of Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan, and Turkmenistan.
On Russia, Negroponte voiced concerns about President Vladimir Putin's drive to centralize power and assert control over civil society, growing state control over strategic sectors of the economy, and widespread corruption.
(AP, AFP)