Iran's top security official says Washington's "bitter confession" of back-to-back political and military failures in the Middle East despite spending billions of dollars has led its allies admit that the region is a safer place without the United States.

In a short note published on Monday, Secretary of Iran's Supreme National Security Council (SNSC) Ali Shamkhani referred to three facts admitted by senior American officials in the past two months.

First and foremost, he said, Washington came under pressure from Riyadh to respond to the September strikes by Yemen on the Aramco oil facilities, but the US clearly snubbed the request and did not put itself in harm's way for the sake of Saudi Arabia.

Then came President Donald Trump's announcement that the US had "foolishly" spent $8 trillion in the Middle East for nothing, Shamkhani said.

Finally, the US turned its back on its Kurdish allies after Turkey decided to launch an incursion into northern Syria, he added.

Shamkhani also touched on Trump's announcement that the US military involvement in the Middle East was the "worst decision ever made."

"It seems that the US administration has come to the conclusion through objective experience that the equation of power and political geometry of the world has changed, especially at its heart, the Middle East, and that the United States can no longer claim absolute authority over the affairs of the international system."

He added, "America has realized that it has only two options; either to be just content with an empty mask of being a global superpower despite heavy costs, or to adopt a realistic approach and acknowledge the present reality of the globe and rid itself of hefty costs of this unmasked masquerade."

Shamkhani touched on the US inability to execute its strategic projects such as the "new Middle East," "the deal of the century," regime change in Iran, Saudi Arabia as the regional gendarme, the Yemen war, the Afghan peace plan and the Syria crisis.

"The ruling US administration's confession has led many countries in the West Asia, even those who have been facilitating and hosting the American presence in the region for years, to acknowledge that the Middle East is a safer place without America," he said.