WASHINGTON — President Donald Trump and his administration are offering a public vote of confidence for Saudi Arabia's young crown prince who, in just days, has upended the royal family, ramped up the kingdom's confrontation with Iran and issued war threats against Lebanon.

Saudi Arabia's efforts to crack down on Iranian influence across the region come on the heels of similar moves by the Trump administration, which recently declared that Iran was not in compliance with its obligations under the Obama-era nuclear agreement. Trump rolled out his Iran policy last month in a scathing speech during which he offered a rap sheet of destabilizing activities by Iran across the Middle East.

At the heart of this effort is Saudi Arabia's 32-year old Crown Prince Mohammed bin Salman, who, since passing over dozens of relatives to become first in line to the throne in June, has ramped up pressure against Iran, accusing it of waging proxy wars across the Arab world, through Shiite groups in Yemen, Syria, Lebanon and Bahrain.

Late last month, Prince Mohammed, widely known as MBS, met with Trump's son-in-law and senior adviser, Jared Kushner, with whom he is said to have formed a close personal relationship. U.S. and foreign officials told NBC News that the two men discussed Kushner's efforts to broker an agreement between the Israelis and Palestinians, and discussed curbing Iranian and Hezbollah aggression against Israel.

The prince recently took a number of bold and unprecedented steps at home, consolidating power by arresting 11 princes — part of a public anti-corruption crackdown that sent shockwaves across the Arab world. The young Saudi heir has also pledged to destroy extremism and return the kingdom to "moderate Islam."

Related: Prince Aims to Rebrand Saudi Arabia From 9/11 Hotbed of Extreme Islam

Trump applauded his actions on Twitter, saying Monday that the crown prince and his father, King Salman, "know exactly what they are doing."

"Some of those they are harshly treating have been 'milking' their country for years!" Trump wrote.

A State Department spokeswoman issued a qualified message of support for the crown prince's actions Tuesday. "We continue to encourage Saudi authorities to pursue the prosecution of people they believe to be corrupt officials. We expect them to do it in a fair and transparent manner."

"Some of those they are harshly treating have been 'milking' their country for years!"

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For Saudi Arabia, which has been at odds with Iran for decades, the effort to assert its dominance in the region took on new urgency Saturday when it intercepted a ballistic missile aimed at the airport in Riyadh. Saudi Arabia quickly accused Iran-backed Houthi militants in neighboring Yemen for the strike.

On Tuesday, Trump's ambassador to the UN, Nikki Haley, supported Saudi Arabia's claims that the missile was fired from Yemen, describing the weapon as an "Iranian Qiam," that may be "of Iranian origin."

"By providing these types of weapons to the Houthi militias in Yemen, Iran's Islamic Revolutionary Guard Corp‎s is violating two UN resolutions simultaneously," Haley said in a statement.

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Her assessment, however, was contradicted by the State Department, which said Tuesday that it was continuing to assess the attack and doesn't have "a full determination as to who is responsible."

U.S. intelligence sources said that there is no evidence Iran was behind the missile launch. One former official pointed out North Korea has also contributed to that arsenal.

White House senior advisor Jared Kushner arrives to join U.S. President Donald Trump and the rest of the U.S. delegation to meet with Saudi Arabia's King Salman bin Abdulaziz Al Saud at the Royal Court on May 20, 2017 in Riyadh, Saudi Arabia. Jonathan Ernst / Reuters file

Trump didn't comment about the attack itself while traveling in Tokyo this week, but hailed the U.S. technology that averted disaster.

"Our system knocked the missile out — out of the air," he said. "That's how good we are. Nobody makes what we make. And now we're selling it all over the world."

In response to the attack, Saudi Arabia has vowed to ramp up its military campaign against the Houthis, as well as against Hezbollah. Lebanon's Prime Minister Saad al-Hariri suddenly resigned on Saturday during a visit to the kingdom, saying his life was at risk. Hariri described Hezbollah as "Iran's arm" in Lebanon and said it has "built a state within a state."

President Donald Trump holds a bilateral meeting with Saad Hariri, prime minister of Lebanon, in the Oval Office at the White House on July 25, 2017 in Washington. Zach Gibson / Pool via Getty Images file

In an interview late Monday with Riyadh-based al-Arabiya television, the Saudi minister of Gulf affairs, Thamer al-Sabhan, said that Lebanon had declared war against Saudi Arabia because of what he described as aggression against the kingdom by the Iran-backed Hezbollah.

"We will treat the government of Lebanon as a government declaring war on Saudi Arabia due to the aggression of Hezbollah," he said in response to the recent decisions taken by the Lebanese government.

Iran's foreign minister Javad Zarif lashed out on Twitter against Saudi accusations of Iranian aggression.

"Visits by Kushner & Lebanese PM led to Hariri's bizarre resignation while abroad. Of course, Iran is accused of interference," he said. "#KSA bombs #Yemen to smithereens, killing 1000's of innocents including babies, spreads cholera and famine, but of course blames Iran."

Hezbollah's leader Hassan Nasrallah quickly blamed Saudi Arabia for Hariri's resignation, saying it was "not his intention, not his wish and not his decision" to quit. Hariri, the son of slain Lebanese Prime Minister Rafik al-Hariri, has maintained close ties with Riyadh, despite accusations that he has been too weak to cap Hezbollah's power and influence in Lebanon and beyond.

Hezbollah fighters, backed by Iran, have helped to prop up Syria's President Bashar al-Assad through that country's ongoing civil war. The group, whose fighters played a major role in forcing Israel to withdraw from southern Lebanon in 2000, enjoys strong support in the Lebanese Shi'ite community. Its members include government ministers, parliamentarians, and local councilors.

"The Saudis are more than willing to take matters into their own hands," said Steven Cook, a Middle East expert with the Council on Foreign Relations. Trump can "egg the Saudis on to take on Iran and Hezbollah, but he doesn't have to do anything, which is exactly how this administration seems to be going about things."

However, early indications suggest that despite its cozy relationship with the Trump administration, Saudi Arabia is hedging his bets on whether Trump's inexperienced team can broker peace in the Middle East and in some cases, is taking matters into its own hands.

Last month, King Salman was in Moscow, urging President Vladimir Putin to moderate Iranian activities in Syria. But Saudi Arabia is also looking to secure more permanent Russian cooperation. Trump, perhaps sensing the competition, tweeted last weekend that he hopes to see Saudi Arabia's Aramco, the most valuable company in the world, listed on the New York Stock Exchange.

"Russia waits for America to make mistakes, then moves in," said Rami Khoury, a Lebanese political expert and professor at the American University in Beirut. "Sometimes, dramatically."