(Reuters) -Slovakia has to reserve the right to decide how fast to raise spending towards NATO's new targets for 2035 and any increase in outlays next year will go to dual-use projects like roads and hospitals, Prime Minister Robert Fico said on Monday.

NATO members agreed on Sunday to a big increase in their defence spending target to 5% of gross domestic product, as demanded by U.S. President Donald Trump.

However Spain said on Sunday it did not need to comply with the 5% target, just days before a summit in The Hague that is meant to be a show of unity. NATO Secretary General Mark Rutte insisted on Monday that Spain would have to hit the new goal.

Fico referred to Spain's objection to the target, which is due to be approved by NATO leaders on Wednesday.

"Slovakia has other priorities than armament in the coming years, at a time of healing public budgets and catching up with the average EU living standard," Fico said in a statement.

"Slovakia must, similar to Spain, reserve the sovereign right to decide at what pace and in what structure it is prepared to increase the Defence Ministry budget with the aim of achieving the NATO target in 2035," he said.

Fico, who has diverged from most Western allies by visiting Moscow twice since last year and refusing to provide official military aid to Ukraine, has also started hinting that he would be in favour of leaving NATO.

Last week, he said neutrality would bring benefits to Slovakia, questioning for the first time the central European country's membership in the alliance that is rushing to bolster its deterrence against Russia.

Slovak President Peter Pellegrini said that he would not break the NATO consensus at the summit.

Fico again posed the question of NATO membership on Monday.

"Slovakia is a NATO member country and has to decide if it respects commitments of our membership or will take a different solution in the future," he said.

"On the top of that, Slovakia is able to achieve NATO requirement even without a marked increase of spending on armament to 5% of gross domestic product."

(Reporting by Jan Lopatka in Prague, Editing by William Maclean)