Iran has urged the US to stop supplying arms to “main sponsors of terrorism” after President Donald Trump clinched a massive military deal with Saudi Arabia on his first visit to the Middle East.

Foreign Ministry spokesman Bahram Qassemi called on Washington on Monday to abandon its "policy of warmongering, meddling, Iranophobia and sales of dangerous and useless weapons to the main sponsors of terrorism."

"Unfortunately, under the hostile and aggressive policies of the American statesmen, we are witnessing a renewed strengthening of terrorist groups in the region and miscalculation of the dictatorships which support these groups," he said.

Qassemi hit out at Trump's accusations that Iran was funding, arming and training "terrorists, militias and other extremist groups that spread destruction and chaos across the region.”

"Once again, by his meddling, repetitive and baseless claims about Iran, the American president tried to encourage the countries of the region to purchase more arms by spreading Iranophobia," the spokesman said.

"It is surprising that Iran is being accused of destabilizing the region by a country which has been an accomplice to the Zionist regime's crackdown on the oppressed Palestinian nation through all-out arms, financial and intelligence support for decades," Qassemi said.

In recent years, the US "has been complicit in the massacre of the defenseless Yemeni people through arming certain Arab regimes in the Persian Gulf," he added.

The official touched on US role in "creating and cultivating Takfiri-terrorist currents, including Daesh" and strongly criticized "deceitful stances, meddlesome statements, and destructive measures" of the new US administration.

Such measures, he said, are aimed at "confronting people's rule on their destiny in the regional countries and consolidating the position and superiority of the Zionist regime."

"US support and that of its regional allies for terrorists is so obvious that their escape forward and accusations of terrorism support against others have no buyers," Qassemi said.

"If financial, arms and intelligence resources of Daesh, Nusra Front and other terrorist groups are cut, they will be finished easily. They resist because these countries' support for the terrorists continues," he added.

His remarks came a day after Trump ended his visit to Saudi Arabia where arms deals worth $110 billion were signed.

Qassemi said, "Regional countries, instead of spending billions of dollars from their people's assets on an illusory American support, had better think about the real stability, welfare, tranquility and peace of their people and spend these exorbitant sums on development and constructive regional cooperation."

Qassemi deplored that "certain regional countries, instead of depending on the power of their people and regional cooperation capacities, have set heart on the support of big powers."

Those countries, he said, "are paving the way for vital infrastructures of the regional countries to weaken and collapse, a case in point being the deplorable situation of Yemen and destruction of Syrian infrastructures by Takfiri terrorists."

Trump's accusations against Tehran came shortly after Hassan Rouhani was re-elected president.

Qassemi said the US and its allies "should know that Iran, as a democratic, stable and powerful country enjoying popular support, is a harbinger of peace, tranquility and good neighborliness in the region and a front-runner in the global fight against violence and extremism," and that Tehran would not go off this course with the hostile rhetoric of those countries.