Spain, Norway and Ireland said on Wednesday that they would recognize an independent Palestinian state, delivering a diplomatic blow to Israel that showed the country’s growing isolation on the world stage more than seven months into its devastating military offensive in the Gaza Strip.

In closely coordinated announcements, the leaders of the three countries said that Palestinian independence cannot wait for a negotiated peace deal with Israel’s right-wing government, which largely opposes a two-state solution, has been expanding settlements in the Israeli-occupied West Bank and is continuing to bombard Gaza without either toppling Hamas or bringing home all its hostages.

Prime Minister Benjamin Netanyahu of Israel has also frustrated world leaders — and two members of his war cabinet — with his refusal to establish a postwar plan to govern Gaza, where the health authorities say that more than 35,000 people have been killed.

Simon Harris, the Irish prime minister, linked his government’s decision to Ireland’s quest for independence from Britain. “From our own history, we know what it means: Recognition is an act of powerful political and symbolic value,” he said at a news briefing.

The announcements by all three countries came just days after the International Criminal Court’s chief prosecutor requested arrest warrants for Mr. Netanyahu and Israel’s defense minister, Yoav Gallant, on suspicion of war crimes. He also sought warrants for three top leaders of Hamas.