U.S. President Donald Trump called Hizbullah a threat to Lebanon and the entire Middle East on Tuesday, accusing it and Iran of fueling a humanitarian disaster in Syria.

"Hizbullah is a menace to the Lebanese state, the Lebanese people and the entire region," Trump said at a joint press conference alongside Prime Minister Saad Hariri at the White House.

"The group continues to increase its military arsenal which threatens to start yet another conflict with Israel... With the support of Iran, the organization is also fueling humanitarian catastrophe in Syria," the U.S. president added.

“Lebanon is on the frontlines against the terrorism of ISIS, al-Qaida and Hizbullah,” Trump went on to say.

Asked about the possible sanctions on Hizbullah, the U.S. leader said: "I'll be making my position very clear over the next 24 hours."

Trump also pledged additional support for the Lebanese army and hailed its role in the fight against IS and other terrorist groups.

Hariri for his part stressed that the Lebanese government “is committed to U.N. Security Council Resolution 1701 as well as all UNSC resolutions.”

“We also discussed the pressures Lebanon is facing as a result of 1.5 million Syrian displaced in our country,” he added.

“I thanked President Trump for his support to our army and security agencies as well as his support to UNIFIL,” Hariri said at the press conference.

He added: “We discussed the efforts Lebanon is making to safeguard our political and economic stability while combating terrorism.”

In brief remarks before an expanded meeting with aides, Trump and Hariri had pledged to fight terrorism to the end.

Hariri said he hopes the partnership between the U.S. and Lebanon against terrorism will continue until terrorists are defeated.

Trump responded, "We will do that."

The U.S. president also said Lebanon is winning the fight against the Islamic State group and others and that "ultimately you will win ... we have great confidence in you."

Hariri had on Monday met at the World Bank Headquarters in Washington with the Lebanese staff at the World Bank and the International Monetary Fund, his media office said in a statement.

The meeting was held in the presence of members of the Lebanese delegation, Executive Director of International Bank for Reconstruction and Development Merza Hassan, Executive Director at the IMF Hazem Beblawi and Director of the Middle East and Central Asia Department at the IMF Jihad Azour.

Hariri assured that his “only concern is to preserve Lebanon, try our best to protect its stability and improve the economy."

"We are seeking to develop partnership with the bank (World Bank) to be able to improve the Lebanese economy, particularly at this difficult stage, whether in respect to growth in Lebanon or the deficit from which we are suffering in light of the presence of the displaced Syrians,” he added.

The PM noted that the government is “looking for ways to create job opportunities and working on an investment plan for the infrastructure, including electricity, water, communications and all the other sectors, which will allow tourism, agriculture, industry and other sectors to develop.”

Turning to the repercussions of displaced Syrians on Lebanon's infrastructure, he said: “Before the Syrian crisis, the infrastructure in Lebanon was already worn out, and today with the one million and a half displaced Syrians you can imagine the weariness in these infrastructure.

“But, we were able with the President to reach a political solution based on protecting the country from all that is happening outside and supporting the country from the inside by introducing projects related to progress,” he said.

Hariri assured that despite some political differences “we agreed that this political dispute will not hinder the governmental work.”

“We are also working to approve the gas and oil draft law as soon as possible and it will be ratified in parliament in the next few weeks. We also approved the salary scale with all the reforms that were included,” added the PM.

“The situation in Lebanon is difficult but not impossible,” he concluded.

Earlier on Monday, Hariri kicked off his official visit to the United States by meeting a number of U.S. Congress officials in Washington.