Donald Trump postponed at the last minute a planned U.S. military operation against the Houthis in Yemen, amid concerns about the consequences that a new military engagement could have on the wider Middle East, according to NBC News.

According to U.S. government sources cited by the network, the strikes against the pro-Iranian rebels had been scheduled to begin at 5:00 p.m. Sunday, but the decision to cancel them was made approximately three hours earlier, at 2:00 p.m.

The possibility of future attacks has not been ruled out, according to an official who spoke on condition of anonymity.

Pressure from Saudi Arabia and the Houthi Threat

The White House decision came after renewed calls from the Saudi crown prince for U.S. intervention, according to a report by the New York Times.

The Houthis have threatened to advance toward Marib, a strategically important area of Yemen where the country’s largest oil infrastructure is located.

Within the U.S. administration, however, there appears to have been considerable concern over the prospect of a new military campaign.

Objections at the Pentagon

According to NBC News, some senior military officials argued that opening another front in the Middle East would be the wrong choice.

They expressed concerns about the U.S. military’s depleted stocks of defensive weapons and long-range munitions, while noting that the Houthis have not attacked U.S. ships.

An official also said that an attack on the Houthis could increase the risk to U.S. troops stationed in the region.

In the past, U.S. attacks against Iranian targets have triggered retaliation from Tehran, including missile and drone attacks against oil facilities in the Gulf and U.S. military forces in the region.

The Other Side: “Inaction Would Send the Wrong Message”

Other military officials, however, supported the operation, arguing that failing to carry out a strike would amount to abandoning an important ally.

According to this view, the U.S. should strengthen Saudi Arabia’s position and support its efforts to maintain air superiority in the region.

The debate intensified after the Houthis claimed that they had shot down a Saudi F-15 fighter jet on Sunday.

Yemen Appeals to Trump for Help

Meanwhile, the head of Yemen’s Presidential Leadership Council, Rashad al-Alimi, had a phone conversation with Donald Trump, requesting U.S. support against the pro-Iranian rebels, according to a source from his office who spoke to AFP.

According to the same source, Trump did not commit to providing military assistance. However, he expressed his support for the country’s government, which is under intense pressure from Houthi forces.