Jordan on Tuesday condemned an Israeli minister’s plan to extend the high-speed Tel Aviv-Jerusalem rail line to the Western Wall holy site in the capital’s Old City.

Calling the plan a “flagrant violation of international law,” Amman’s foreign ministry spokesman Daifallah al-Fayez called on the international community to “assume its responsibilities to resist the illegitimate and illegal Israeli steps,” according to comments carried by the BBC.

The Jordanian anger was sparked by the announcement a day earlier by Transportation Minister Bezalel Smotrich that officials had approved moving forward with a controversial plan to place a train station at the heart of the Old City that could whisk tourists from Ben-Gurion Airport to the Western Wall, the holiest site where Jews are allowed to pray.

In a statement, Smotrich’s office said Monday the plan, initiated by his predecessor Israel Katz, had been delayed over the past year, without elaborating.

However, following a directive from Smotrich, the National Planning and Building Council approved a new route for the train, the Transportation Ministry said. It did not specify the details of the altered route.

The plan involves extending the high-speed Jerusalem-Tel Aviv train line from its current terminus near Jerusalem’s Central Bus Station to a new station in the Old City via an underground tunnel. The plan would involve constructing two underground stations and excavating over two miles (three kilometers) of tunnel beneath downtown Jerusalem and under the politically and historically sensitive Old City — a project likely to raise fierce opposition by archaeologists, religious authorities and Palestinians.

Jordan opposes Israeli development in Jerusalem’s Old City. The Jordanian monarchy is seen by both Israelis and Palestinians as the “custodian” of the city’s Muslim holy sites, and has long opposed what it sees as Israeli encroachment through construction and infrastructure projects in and around Temple Mount , the most sacred site in Judaism and the third-holiest in Islam.

Smotrich on Monday praised the approval as “historic,” adding in a statement that the new train line “is huge news for Israeli residents and the millions of tourists who come to Jerusalem.”

The plan was first introduced by former transportation minister Katz in 2017, who said the Old City train station would be named after US President Donald Trump after the latter’s recognition of Jerusalem as Israel’s capital.

Transportation Ministry spokesman Avner Ovadia said at the time that the project was estimated to cost more than $700 million and, if approved, would take four years to complete. The cost and time are partly a function of the need to cut the tunnel through bedrock across the mountainous capital.

This past December, the long-awaited Jerusalem-Tel Aviv train began running at full capacity every hour for the first time, though the line only goes as far as the Hagana station in southern Tel Aviv and will not reach stations in the center and north of the coastal metropolis until later this year.

The train opened in 2018 after years of delays, but at first only took riders between Jerusalem and Ben-Gurion International Airport, as work crews labored to electrify the line all the way to Tel Aviv. Riders were forced to switch trains at the airport, adding some 20 minutes to the journey.

The train replaces a British Mandate-era rail that for decades wound its way between Tel Aviv and southern Jerusalem via scenic mountain passes, taking nearly two hours to make the journey between the two cities, which lie roughly 70 kilometers (45 miles) apart.

The new line is one of the largest civil engineering projects undertaken by the state of Israel, and includes several long bridges and tunnels intended to allow the train to maintain a high speed through the Jerusalem hills, including an iconic 40-meter-high (131-foot-high) viaduct stretching over a kilometer through the Ayalon Valley.

Construction on the fast train began in 2001, and the original launch date was in 2008, twelve years ago. It was then repeatedly delayed, first to 2014, twice in 2018 and again to 2019. The launching of the Jerusalem-Ben Gurion line, in October 2018, was marred by repeated malfunctions, delays and shutdowns.