Italy will comply with a new NATO spending target of 5 percent of gross domestic product (GDP) on defense and security, Prime Minister Giorgia Meloni said on Monday, but it will take 10 years to do so.

A NATO summit, scheduled to run from Tuesday to Wednesday, is expected to push the alliance's members to boost defense spending to 3.5 percent of GDP from the current 2 percent and commit a further 1.5 percent to broader security-related spending, meeting U.S. President Donald Trump's demand for a 5 percent overall target.

Meloni said highly-indebted Italy had managed to ensure that each country could stipulate what constitutes spending on security, leaving some leeway on a contentious issue.

"These are important commitments that Italy intends to honor. We will not leave our country weak and unable to defend itself," Meloni added.

In a related development, Spain on Sunday agreed with NATO to cap its military spending at 2.1 percent of GDP. "Spain will need to allocate 2.1 percent of its GDP to acquire and maintain all the personnel, equipment, and infrastructure requested by the Alliance to address emerging threats and challenges," Spanish Prime Minister Pedro Sanchez stated at a press conference at La Moncloa Palace. "No more, no less."

Last week, Sanchez formally rejected the 5 percent target, emphasizing that Spain has no intention of committing to such a level.

The 5 percent defense spending target is expected to be the focal point of this week's NATO summit. While Italy and Spain remain hesitant to commit to shared strategies or timelines, some other countries including Estonia, which said it would meet the five percent goal by next year and urged other nations to follow suit within five years, are pushing for a more proactive collective defense role. 

Experts argued that the ongoing disagreement underscores deeper concerns about NATO's unity, military capabilities and its long-term strategic vision.

"If NATO cannot agree on its main purpose, then even well-funded forces will lack shared direction," said Stefan Wolff, professor of international security at the University of Birmingham. "Without unity, the 5 percent target becomes just another political gesture to buy time."

Wolff warned that even if NATO members meet the proposed 5 percent target, without prioritization and coordinated defense-industrial development, such spending risks becoming "financial inflation without strategic output."

Li Haidong, a professor at China Foreign Affairs University, said that expanding defense spending is a huge challenge for NATO's European member states and could place heavy pressure on the economic and social development of these countries, adding that it's a goal that is very difficult to achieve in the short term.

Noting that NATO is increasing military spending while there is growing concern about security among various countries, Li said it indicates that divisions within NATO are unlikely to ease in the future; rather, they will continue to intensify. 

The weakening of internal cohesion and the growing recognition of its destructive impact in the international community will make it difficult for NATO to maintain or strengthen its influence, Li said.

(With input from agencies)