ROME (Reuters) - Italy is planning to improve weaponry aboard some of its F35 fighter jets, a defence ministry document showed, in what analysts see as a move to secure well-stocked, up-to-date arsenals in the wake of Russia's invasion of Ukraine.

The document, which parliament must review by the middle of August, envisages 682 million euros ($746 million) of purchases over a 14-year period on armaments including guided bombs, missiles and 25 mm cannon rounds.

The programme comes at a time of increased defence spending by NATO members including Italy, which is separately planning a large investment on new Eurofighter jets.

Rome defence spending equals some 1.5% of GDP -- below a 2% NATO alliance target. Other European nations have sharply increased their defence budgets since Moscow initiated its war against Kyiv in February 2022.

The government document says it had already earmarked 650 million euros for its armaments programme which aimed to support operations over a hypothetical six-month period of conflict.

Alessandro Marrone, a defence analyst at Istituto Affari Internazionali (IAI) said it was routine for governments to replenish their arsenals, but Western nations were changing their procurement plans to be ready for large scale conflicts.

He said in the past they risked running out of ammunition in contexts including the 1998-99 Kosovo war and the 2011 military intervention in Libya, and defence authorities were aiming to avoid such a risk in future.

"They are gradually shifting their investment towards assets for conflicts with equal adversaries, like Russia, which are different from anti-terrorist or anti-guerrilla operations like those they had in Iraq and Afghanistan," he told Reuters.

($1 = 0.9142 euros)

(Reporting by Angelo Amante; Editing by Crispian Balmer)

By Angelo Amante