MADRID (AP) — Spain has rejected a NATO proposal to spend 5% of GDP on defense needs that’s due to be announced next week, calling it “unreasonable.”

In a letter sent Thursday to NATO Secretary-General Mark Rutte, Spanish Prime Minister Pedro Sánchez said that Spain “cannot commit to a specific spending target in terms of GDP” at next week’s NATO summit in The Hague.

Most U.S. allies at NATO are on track to endorse U.S. President Donald Trump’s demand that they invest 5% of gross domestic product on their defense and military needs. In early June, Sweden and the Netherlands said that they aim to meet the new target.

Spain is the lowest spender in the 32-nation military alliance, directing less than 2% of its GDP on defense expenditure.

In April, Sánchez said the government will raise defense spending by 10.5 billion euros ($12 billion) to reach NATO’s previous target of 2% of GDP.