As tensions escalate in the Middle East, high-ranking military officials from the United States and Russia have converged in the region for emergency planning.

The catalyst for the urgent visits appears to be the looming threat of an Iranian attack on Israel, predicted to occur 'imminently', according to US intelligence.

A high-ranking Russian delegation led by Sergei Shoigu, the Secretary of Russia's National Security Council, arrived in Tehran. The purpose of the visit, according to the Secretariat of the Supreme National Security Council of Iran, is to strengthen political and security ties and to discuss regional and international issues. However, the timing of Shoigu's arrival coincided with heightened military preparations and international concern.

Meanwhile, Michael Erik Kurilla, the commander of the United States Central Command (CENTCOM), arrived in Israel on Saturday. Although a US official stated that Kurilla's trip was planned before the recent surge in tensions, it is now expected to serve as a crucial opportunity to bolster the international coalition defending Israel.

Earlier, Pentagon spokesman Pat Ryder announced that US Secretary of Defense Lloyd J. Austin discussed regional tensions with Israeli Defense Minister Yoav Gallant on Sunday.

On Monday, US Secretary of State Anthony Blinken and his Qatari counterpart Mohammed bin Abdulrahman Al Thani spoke on the phone to discuss the possible attacks by Iran and Hezbollah against Israel, stressing the need for de-escalation, according to Axios journalist Barak Ravid.

French President Emmanuel Macron said he has spoken with UAE President and Saudi Crown Prince on the situation.

"We call on all stakeholders to show responsibility and restraint to avoid a regional conflagration. No one has any interest in escalation," he said.

During a visit to the underground command center of the Israeli Air Force, Israeli Defense Minister Yoav Gallant highlighted the country's readiness to transition swiftly to offensive operations if necessary.

"Our enemies are carefully considering their every move because of the capabilities you have demonstrated over the past year. Nevertheless, we must be prepared for anything – including a swift transition to offense," he said.

Several countries have advised citizens to leave Lebanon and Iran. The situation has led to airlines, including Lufthansa, Delta, and others, suspending flights to the region due to the escalating risks.

In Lebanon, the World Health Organization has delivered 32 tons of medical supplies in anticipation of potential war casualties, reflecting the increasing likelihood of a broader conflict involving Hezbollah and Israel.

"The goal is to get these supplies and medicines to various hospitals and to the health sector in Lebanon, especially in the places most exposed (to hostilities) so that we can be ready to deal with any emergency," Lebanon’s Health Minister Firass Abiad told reporters at the airport landing strip where the aid arrived.

Meanwhile, Beirut airport has seen a surge in people attempting to leave the country, indicating widespread fear of an impending full-scale war.

Iranian officials have at the same time continued their inflammatory rhetoric. On Monday, Ali Bagheri Kani, the Acting Foreign Minister of Iran, held a meeting with Khaled Qaddoumi, the representative of the Hamas movement in Tehran. The visit, part of a broader consultation with various ambassadors and foreign mission heads in Tehran, underscores Iran's intention to launch the attack very soon.

Kani emphasized the “moral imperative” to oppose what he described as the "occupation of Palestinian land and the genocide of a nation," framing the situation as one where indifference and appeasement would only “enable further evil.”

Speaking to his Bahraini counterpart, Bagheri Kani said Iran would be "rewarding" Israel if it remains silent following the killing of Ismail Haniyeh. "Therefore, the Islamic Republic considers reciprocal action to be its right, based on international rules and norms," he said.

Hossein Salami, commander-in-chief of the Islamic Revolutionary Guard Corps, criticized Israel's recent actions, calling for a harsh response to what he termed as an Israeli mistake.

"If the Israelis receive a firm response, they will understand that killing Haniyeh was a mistake… The Israelis are constantly making calculation errors, and they have repeated this mistake once again," he said.

Iranian Foreign Ministry spokesman Nasser Kanaani also underscored Iran's determination to retaliate, emphasizing that no external messages were needed to justify their actions.

Backed by the US and an international coalition, Israel braces for a potential Iranian assault, similar to that created in the face of the April 13 bombardment towards Israel. At the time, most of the 350 projectiles were intercepted.