Estimates in Washington, D.C., are that Iran is calibrating its plans for a major retaliatory strike against Israel to send a message — but not ignite a regional war that would force Washington to respond.

Biden administration officials believe that Iran is planning a larger-than-usual air attack on Israel in the coming days, an attack that will likely include a combination of missiles and drone attacks, according to two American officials, who were granted the right to remain anonymous for details of the sensitive discussions, according to the Politico website. ".

Neither official said they were completely confident that Iran would succeed in striking Israel in a way that would not prompt the United States to respond militarily, because any attack increases the risk of a larger conflagration in the Middle East. But Iran is not seeking to expand the regional crisis further, as the Biden administration has long decided, which officials said could affect Tehran's planning.

The National Security Council declined to comment. But President Joe Biden said during a press conference on Wednesday that Iran “threatens to launch a major attack on Israel.”

“Our commitment to Israel’s security against these threats from Iran and its proxies is firm,” Biden continued while standing next to the Japanese Prime Minister. We will do everything in our power to protect Israel's security."

Iranian leaders have explicitly warned in recent days that the country will respond forcefully to the deadly April 1 attack on a diplomatic facility in Damascus. The Iranian Supreme Leader said that Israel must be punished.”

“When they attack the consulate, it is as if they attacked our soil,” Ayatollah Ali Khamenei said on Wednesday. “The evil regime (Israel) has made a mistake and must be punished, and it will be punished.”

The Biden administration expects Iran to respond in the coming days, as early as this weekend, according to one US official. “We are still in that window” for an Iranian response, the second official said. But Iran "is looking to calibrate it, so that it does not overestimate its power."

The first US official said that the United States is sending direct messages to Iran through existing channels, mainly to ensure that any attack does not increase tensions in the Middle East.

US officials usually communicate through other parties with Iran, with which Washington has not established official diplomatic relations for more than 45 years. But direct contacts are possible, including through Iran's mission to the United Nations.

Nate Evans, spokesman for the US mission to the United Nations, said his office is not discussing diplomatic talks. Iran's mission to the United Nations did not immediately respond to a voicemail message seeking comment. The Israeli Embassy in Washington did not immediately respond to a request for comment.

State Department spokesman Matthew Miller told reporters Thursday that Secretary of State Antony Blinken spoke with senior officials from other countries, including Turkey, China and Saudi Arabia, this week, and asked them to warn Iran against deepening the crisis.

Miller added: “We have also reached out to European allies and partners over the past few days and also urged them to send a clear message to Iran that escalation is not in Iran’s interest, not in the region’s interest, and not in the world’s interest.”

Brett McGurk, the White House's top Middle East official, has also spoken in recent days with leaders in Saudi Arabia, the United Arab Emirates, Oman and Iraq, to better prepare for what is to come as well as to pass messages of de-escalation to Iran.

In a phone call with Defense Secretary Lloyd Austin on Thursday, Israeli Defense Minister Yoav Galant warned that Israel would respond to any Iranian attack. Gallant told Austin that “a direct Iranian attack would require an appropriate Israeli response against Iran,” according to a transcript of the call. “The State of Israel will not tolerate any Iranian attack on its territory.”

The United States expects Iran to use a combination of drones and missiles in the strike, which could come from Iran itself, its proxies in the region — such as Lebanon's Hezbollah, which is located directly on Israel's northern border — or a combination of both.

Officials did not clarify whether Iran was planning to strike Israeli military assets or civilian targets. But experts said the scope of the expected Iranian response would determine whether the situation would worsen.

Experts believe that the severity and success of this strike is likely to be a decisive factor in determining whether this escalates into a regional conflict.