(CNN) Newly re-elected Iranian President Hassan Rouhani dismissed US President Donald Trump's visit to Saudi Arabia over the weekend as a "theatrical gathering" that would do nothing to combat terrorism in the region.

In a news conference in Tehran on Monday, Rouhani said Trump's first visit abroad was a "theatrical gathering with no practical or political value."

"You can't solve terrorism just by giving your people's money to a superpower," Rouhani said.

He was referring to a $110 billion military deal Trump clinched with Saudi Arabia during the US President's first foreign trip since he took office, one of the biggest arms sales in history.

Earlier Monday, Iranian Foreign Ministry spokesman Bahram Qassemi called on Washington to abandon its "warmongering policy, intervention, Iranophobia and sales of dangerous and useless weapons to the main sponsors of terrorism," according to state-run Press TV.

"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 was reported as saying.

Using more measured tones, Rouhani said Tehran was waiting before passing any judgment on the new government in Washington.

The 68-year-old leader also said the US had been wrong in its interventions in Afghanistan, Syria and Yemen.

"The Americans do not know our region. That's the problem. Those who are advising the Americans are unfortunately rulers who deviate America with unsound advice or buy some influence in the US with their money," he said.

In a further dig at Iran's biggest rival in the Middle East, Saudi Arabia, Rouhani reiterated the Iranian assertion that Saudi Arabia had been behind the September 11, 2001 terror attacks in the US in which nearly 3,000 people died.

He said people in the US would not be willing "to exchange what they lost in the 9/11 terrorist attacks for certain sums and then forgive those acts."

Trump says Iran is region's main sponsor of terrorism

In a speech to Arab Muslim leaders in Riyadh on Sunday, Trump singled out Iran as the world's biggest sponsor of terrorism.

"From Lebanon to Iraq to Yemen, Iran funds, arms, and trains terrorists, militias, and other extremist groups that spread destruction and chaos across the region," Trump said.

"For decades, Iran has fueled the fires of sectarian conflict and terror. It is a government that speaks openly of mass murder, vowing the destruction of Israel, death to America, and ruin for many leaders and nations in this room."

Rouhani, a pragmatist and in Iranian terms a moderate, was re-elected for a second term with 57% of the vote in presidential elections last Friday, promising better relations with the rest of the world and more jobs for Iran's young people.

In his news conference, Rouhani vowed to defeat terrorism in the region during his four-year term.

He also said Iran would continue with its ballistic missile program.

"Our missiles are for peace and for defense... American officials should know that whenever we need to technically test a missile we will do so. We don't need their permission."

Rouhani was a key architect of the 2015 nuclear deal with the US, the European Union and other partners.

His first term was marked by an emergent international outreach, an approach supported by then-US President Barack Obama.

Trump meets with Israeli President Reuven Rivlin in Jerusalem on Monday.

On Monday Trump arrived in Israel, where he again singled out Iran. Standing next to Israeli President Reuven Rivlin, Trump said: "The United States and Israel can declare with one voice that Iran must never be allowed to possess a nuclear weapon, and must cease its deadly funding, training and equipping of terrorists and militias."

The nuclear agreement has been controversial in both the US and Iran, and it emerged as a top campaign issue in Iran's election.

Under the agreement, Iran pledged to reduce its stockpile of low-enriched uranium by 98% and significantly scale back its number of installed centrifuges.

In exchange, the US and the EU lifted some of the sanctions that have crippled the country's economy.

The fall in global oil prices has dented most of the economic benefits the opening of markets in the West may have had on Iran, leading to accusations from opponents Rouhani has not honored his promises.

Conservative clerics were also angered by the fact that men and women danced together in the streets of Tehran following Rouhani's election victory, testing the country's strict segregation rules, Reuters reported.