HAVANA, Dec. 21 (Xinhua) -- Cuban President Raul Castro reiterated Thursday that Cuba is not responsible for the alleged "acoustic attacks" on U.S. diplomats here.

So far neither Cuban nor American experts have found any evidence that could support the accusation, Castro said at the closing of the plenary session of the National Assembly.

He added that Cuba is not responsible at all for the setback in bilateral ties with the United States.

"The White House fabricates excuses to justify its return to failed policies, which are universally rejected," he said.

Washington said that a group of its diplomats in Cuba had suffered "acoustic attacks" causing symptoms as diverse as deafness, nausea and speech problems.

Havana rejected the accusation, initiated an investigation, and urged the United States to present evidence of the alleged attacks.

The White House has taken a series of retaliation measures, including stopping all consular services, a move that is highly unpopular among Cubans.

Castro reiterated that Cuba is willing to maintain cooperation with the United States and hold negotiations on the basis of mutual respect.