(Israel Hayom/JNS) Israel has managed to secure a written pledge from four successive U.S. presidents, including President Trump, to safeguard its presumed nuclear deterrent, The New Yorker magazine reported on Monday.

According to uncorroborated reports in the foreign media, Israel has as many as 200 nuclear warheads as part of a presumed military nuclear program dating back to the 1960s. Israel has never publicly acknowledged these reports.

Israel has also pledged not to be the first nation to introduce nuclear weapons in the region.

According to a recent report, in the wake of the first Gulf War in the early 1990s, Israel felt that the unwritten understanding struck between U.S. President Richard Nixon and Israeli Prime Minister Golda Meir in the early 1970s to ensure Israel would never be compelled to denuclearize was insufficient.

Eventually, Israeli policymakers convinced U.S. President Bill Clinton to put the Nixon-Meir understandings into writing.

“The first iteration of the secret letter was drafted during the Clinton administration as part of an agreement for Israel’s participation in the 1998 Wye River negotiations with the Palestinians,” said the report, by The New Yorker’s Adam Entous.

“In the letter, according to former officials, President Bill Clinton assured the Jewish state that no future American arms-control initiative would detract from Israel’s deterrent capabilities, an oblique but clear reference to its [alleged] nuclear arsenal.”

The letter was later signed by President George W. Bush, and President Barack Obama ultimately signed “an updated version of the letter.”