French President Emmanuel Macron said on Monday that he would not rule out France delivering fighter jets to Ukraine but warned against the risk of escalation in the conflict.

"Nothing is excluded in principle," Macron said after talks with Dutch Prime Minister Mark Rutte when asked about the possibility of sending jets to Kiev.

However, the French President set out a series of "criteria" before making any decision, as Ukraine steps up calls for more advanced weapons from the West just days after its allies pledged to deliver tanks.

These included that Ukraine must first make the request, that any arms would "not be escalatory," and that they would "not be likely to hit Russian soil but purely to aid the resistance effort."

Macron stressed that any arms delivery "must not weaken the capacity of the French armed forces."

He noted that the Ukrainians "are not making this request at the moment for fighter jets."

Dutch politicians have recently suggested the idea of sending F-16 jets to Ukraine, but Rutte echoed Macron's cautious comments.

"There is no taboo but it would be a big step," the Dutch Premier indicated.

"It is not at all a question of F-16s, there has been no demand (from Ukraine)," he added.

The French and Dutch leaders made their comments a day after German Chancellor Olaf Scholz said he would not send fighter jets to Ukraine.

Scholz only just agreed on Wednesday to send 14 Leopard 2 tanks to Ukraine and to allow other European countries to send theirs, after weeks of intense debate and mounting pressure from allies.

Scholz's decision to green-light the tanks was accompanied by a US announcement that it would send 31 of its Abrams tanks.

Ukrainian President Volodymyr Zelensky said last week however that he wants the West to send long-range missiles and jets.

On Monday, Ukrainian Prime Minister Denys Shmyhal said Kiev expects to receive fighter jets from the West in the near future and it would take Ukrainian pilots at least six months to learn how to operate them.

A couple of days ago, Colonel Yurii Ihnat, the spokesperson for the Air Forces Command of the Armed Forces of Ukraine, said Kiev intends to obtain 24 F-16 fighter jets from its international allies.

Earlier, Polish Prime Minister Mateusz Morawiecki pointed out that Poland can hand over its F-16 fighter jets to Ukraine only in coordination with other NATO partners.

Even though the West has not yet decided on the deliveries of fighter jets, Ukraine has already compiled a list of some 50 pilots, who are ready to start training on F-16s, speak English, and have a track record of "thousands of combat missions," Politico revealed, citing a Pentagon official and a Ukrainian official, as well as three other people familiar with the matter.

Read more: Germany reiterates stance not to send warplanes to Ukraine