FILE PHOTO: Britain's Prime Minister Theresa May speaks to supporters during a visit to Finchley Conservatives in Barnet, London, Britain May 4, 2018. REUTERS/Toby Melville/Pool

LONDON (Reuters) - Britain supports Israel’s right to defend itself against Iranian aggression, Prime Minister Theresa May told her Israeli counterpart Benjamin Netanyahu in a phone call on Thursday.

Israel said it had attacked nearly all of Iran’s military infrastructure in Syria on Thursday after Iranian forces fired rockets at Israeli-held territory for the first time in the most extensive military exchange ever between the two adversaries.

“The Prime Minister condemned the Iranian rocket attacks against Israeli forces, and said we strongly support Israel’s right to defend itself against Iranian aggression,” May’s office said in a statement.

The confrontation came two days after the United States announced its withdrawal, with Israel’s encouragement, from a 2015 nuclear accord with Iran.

Netanyahu said Israel’s air strikes were appropriate because Iran had “crossed a red line”.

The British statement said May and Netanyahu “agreed it was vital for the international community to continue working together to counter Iran’s destabilizing regional activity, and for Russia to use its influence in Syria to prevent further Iranian attacks”.

The British statement added that May had “reiterated our position on the Iran nuclear deal, noting that we and our European partners remain firmly committed to ensuring the deal is upheld, as the best way of preventing Iran from developing a nuclear weapon”.