MADRID (Reuters) -NATO’s support for Ukraine is unbreakable and Russian President Vladimir Putin will not achieve his objectives in the country his forces invaded on Feb. 24, Spanish Prime Minister Pedro Sanchez said on Monday.

The war in Ukraine and the applications by Finland and Sweden to join the defensive alliance that it has triggered are set to dominate a summit of the North Atlantic Treaty Organization in Madrid on June 28-30 that Sanchez will host.

“Supporting Ukraine with determination is the only way to ensure that the Europe and the world we have built has a certain future,” the prime minister told an event marking the 40th anniversary of Spain’s NATO membership.

NATO Secretary General Jens Stoltenberg said at the same event that the “cold blast of conflict” would overshadow the historic summit.

Ukrainian forces were battling on Monday to hold onto the ruined city of Sievierodonetsk in Luhansk province, which has become the focus of Moscow’s offensive as it tries to take control of the eastern Donbas region, one of Putin’s war aims.

Finland and Sweden have formally applied to join NATO following Russia’s invasion of its neighbour, reversing generations of military non-alignment. But Turkey has objected to the Nordic countries joining, holding up a deal that would allow for a historic enlargement of the alliance.

In Madrid on Monday, Stoltenberg said NATO was “ready to defend every inch of allied territory from any threat from any direction” and was providing critical support for Ukraine to uphold its “right to self-defence, enshrined in the UN charter”.

“At the Madrid summit, we will chart the way ahead for the next decade, we will reset our deterrence and defence for a more dangerous world,” the NATO chief said.

(Reporting by Inti Landauro, Writing by Emma Pinedo, Editing by Andrei Khalip and Catherine Evans)