Israel signalled it would not change policy around its assumed nuclear arsenal on Monday as Washington affirmed a global treaty designed to roll back the spread of such weaponry.

The rare, if veiled, remarks by Prime Minister Yair Lapid came as countries party to the 1970 nuclear Non-Proliferation Treaty (NPT) met in New York for a periodic review conference.

Israel has not signed the voluntary NPT, which offers access to atomic energy in exchange for the forswearing of nuclear weaponry.

It has been leading regional calls for world powers to crack down on NPT-signatory Iran's suspected use of civilian nuclear technologies as cover for military designs. Tehran denies wrongdoing.

Addressing the Israel Atomic Energy Commission, Lapid spoke of the country's "defensive and offensive capabilities, and what is referred to in the foreign media as 'other capabilities'".

"These other capabilities keep us alive and will keep us alive as long as we and our children are here," he said, according to a transcript from his office.

Under a decades-old ambiguity policy designed to deter surrounding enemies while avoiding provocations that can spur arms races, Israel neither confirms nor denies having nuclear weaponry.

Scholars believe it does, having acquired the first bomb in late 1966. Israeli journalists, circumscribed by military censorship, often refer cryptically to such capabilities or cite foreign media reporting on them.

Israel's official reticence has also helped stave off scrutiny by the United States, which is formally committed to encouraging NPT observance.

"The U.S. reaffirms our commitment to preserving and strengthening this critical treaty for future generations," U.S. Secretary of State Antony Blinken tweeted as he attended the first day of the NPT conference.

Asked if Lapid's remarks were timed for the conference, or whether Israel had sent an observer as it has in the past, the prime minister's office had no immediate response.

(The story refiles to correct 'our' to 'are' in para 6)

(Writing by Maayan Lubell; Editing by Mark Potter)