Foreigners must tell the Israeli defence ministry if they fall in love with a Palestinian in the occupied West Bank, according to new rules.
If they marry, they will be required to leave after 27 months for a cooling-off period of at least half a year.
It is part of a tightening of rules on foreigners living in, or wanting to visit, the West Bank.
Palestinians and Israeli NGOs have accused Israel of "taking restrictions to a new level".
The new rules are due to come into force on Monday.
The regulations laid out in a lengthy document include a demand on foreigners to inform the Israeli authorities within 30 days of starting a relationship with a Palestinian ID holder.
New restrictions on Palestinian universities include a quota for 150 student visas and 100 foreign lecturers, while there are no such limits in Israeli ones.
Businesspeople and aid organisations say they will also be severely affected. The rules set strict limitations on the duration of visas and visa extensions, in many cases preventing people from working or volunteering in the West Bank for longer than a few months.
"This is about demographic engineering of Palestinian society and isolating Palestinian society from the outside world," says Jessica Montell, executive director of the Israeli non-governmental organisation HaMoked, which has petitioned the Israeli High Court against the regulations.
"They make it much more difficult for people to come and work in Palestinian institutions, volunteer, invest, teach and study."
'One state, two systems'
Israel captured the West Bank from Jordan in the 1967 Middle East War. Today, Cogat, a unit of the Israeli Ministry of Defence, is responsible for the administration of its occupation of the Palestinian territory.
The new 97-page Cogat order is titled Procedure for entry and residence of foreigners in the Judea and Samaria area - the biblical name Israel uses for the West Bank. It was first published in February, but its introduction has been delayed.
The document says it sets out to "define the levels of authority and the manner of processing for applications from foreigners who wish to enter the Judea and Samaria area".
It cites interim peace agreements reached in the 1990s, which required Israeli approval to grant residency to spouses and children of Palestinian residents of the West Bank and Gaza, and approve visitor permits.
The new rules do not apply to those visiting Israel as well as Palestinian-controlled parts of the West Bank, nor Jewish settlements. In such cases, entry involves the Israeli immigration authorities.
The PLO - the umbrella body representing the Palestinian people - has said they bring in "apartheid regulations that impose a reality of one state and two different systems".
The BBC contacted Cogat for a response but did not receive one. Israeli authorities say that restrictions on travel into the territory are needed for security reasons.
A longstanding Israeli ban on granting residency status to foreign spouses of Palestinians in the West Bank means that thousands of people continue to live with an uncertain legal status.
The campaign group, Right to Enter, complains of "discriminatory, cruel and arbitrary practices by Israeli authorities" causing "immense humanitarian difficulties" for foreign spouses which result in them being forcibly separated from their families in the West Bank.
It says the new procedures will only "formalise and aggravate many of the existing restrictions" and "will force many families to move or stay abroad to maintain their family unity."
Some categories of visits to relatives are not listed at all in the new rules, including visits to siblings, grandparents, and grandchildren.
Meanwhile, the European Commission says it has expressed concern about restrictions on foreign students and academics at Palestinian universities to the "highest levels" of the Israeli authorities.
EU response to Israel's new restrictions undermining EU-Palestinian university exchanges under Erasmus+:— Martin Konečný (@MartinKonecny) August 31, 2022
"With Israel itself benefitting greatly from Erasmus+, the Commission considers that it should facilitate and not hinder access of students to Palestinian universities." pic.twitter.com/jBnYE6PbmN
Under its Erasmus+ programme, 366 European higher education students and staff went to the West Bank in 2020. At the same time, 1,671 Europeans were at Israeli institutions.
"With Israel itself benefitting greatly from Erasmus+, the Commission considers that it should facilitate and not hinder access of students to Palestinian universities," European Commissioner Mariya Gabriel has said.
The HaMoked petition to the High Court was joined by 19 individuals.
Bassim Khoury, CEO of a Palestinian pharmaceutical firm in the West Bank, says he would be severely limited in his ability to bring employees, investors, suppliers, and quality control experts from abroad because of visa restrictions and costs of travel.
The new rules specify that foreign visitors coming on a West Bank-only permit are obliged to travel via land crossings with Jordan and can only use Israel's Ben Gurion airport in exceptional cases.
One of Mr Khoury's major investors is Jordanian, and the new rules completely exclude nationals of Jordan, Egypt, Morocco, Bahrain, and South Sudan - although these countries have diplomatic ties with Israel.
Holders of passports from these countries - including dual nationals - can only enter the West Bank in exceptional and humanitarian cases for a limited period.
Another petitioner was Dr Benjamin Thomson, who heads a Canadian charity, Keys to Health, which sends medical professors from North America and the UK to train Palestinian doctors.
"Anyone involved in work in the Occupied Territories of Palestine is already familiar with the multiple administrative delays in getting permission," he says.
"These new regulations make delays worse, increase cost, and decrease the predictability of travel in and out of the West Bank.
"This predictability is essential to be able to do charity work in the West Bank while still being able to continue [doing paid] work outside it," he goes on, suggesting that the new rules may prevent doctors employed elsewhere from being able to volunteer.
In July, the High Court rejected the petition on the rules as "premature," indicating that Cogat had yet to reach a "final decision" on them. However, there have been no changes announced to the procedures officially published online or their scheduled introduction.