President Recep Tayyip vowed Sunday to stand up to "imperialist" forces Sunday as he led Turkish centenary celebrations in the shadow of Israel's escalating war with Hamas militants in Gaza.

Erdogan took centre stage during day-long events that both honoured the republic's secular founder and played up the achievement of his Islamic-rooted party that has run Turkey since 2002.

"Our country is in safe hands, you may rest in peace," Erdogan said after laying a wreath at the mausoleum of military commander and statesman Mustafa Kemal Ataturk.

"We will be successful and victorious. No imperialist power can prevent this," Erdogan added in an evening address in Istanbul.

Ataturk is lionised across Turkish society for driving out invading forces and building a brand new nation out of the fallen Ottoman Empire's ruins in the wake of World War I.

Turkish Air force pilots of the 'Turkish Stars' fly in Northrop F-5 over the Bosphorus as Camlica mosque is seen in the background to mark the 100th anniversary of Turkish Republic in Istanbul on October 29, 2023. Turkey marked its centenary as a post-Ottoman republic on October 29, 2023, with somewhat muted celebrations held in the shadow of Israel's escalating war with Hamas militants in Gaza. (Photo by OZAN KOSE / AFP)

He formed as a Westward-facing nation that stripped religion from its state institutions and tried to forge a modern new identity out of its myriad ethnic groups.

It eventually became a proud member of the US-led NATO defence alliance and a beacon of democratic hopes in the Middle East.

"We are Ataturk's daughters, we are the children of the republic," pensioner Nerguzel Asik said after watching a military parade in Istanbul.

"We feel 'Turkishness' in every way," student Selin Gunes agreed.

Social transformation

But Ataturk's social and geopolitical transformation of the overwhelmingly Muslim nation created divisions that weigh on Turkish politics to this day.

Erdogan tapped into these as he led his conservative Justice and Development Party (AKP) to power over the leftist Republican People's Party (CHP) formed by Ataturk.

He has spent much of the past decade testing the limits of Turkey's secular traditions as well as its ties with the West.

These competing forces were on full display as Erdogan moved from honouring Turkey's past to celebrating his own government's achievements while he was prime minister and president.

Erdogan ended the day by overseeing 100 navy ships pass through the Bosphorus while screaming fighter jets performed aerobatics overhead.

Turkish soldiers carry a flag depicting Turkish Republic founder Mustafa Kemal Ataturk during a parade to mark the 100th Anniversary of the Republic Day in Ankara on October 29, 2023. Turkey marked its centenary as a post-Ottoman republic on October 29, 2023, with somewhat muted celebrations held in the shadow of Israel's escalating war with Hamas militants in Gaza. (Photo by Adem ALTAN / AFP)

"Turkey is a country that helps those who have no one, from the Balkans to the Caucasus, from Palestine to wherever there is a need," Erdogan told the nation.

"The Palestinian rally (in Istanbul) was a part of this."

Palestinian cause

Sunday's celebrations have been partially eclipsed by Erdogan's increasingly fierce attacks against Israel over its response to the October 7 Hamas attacks.

The militants indiscriminantly killed 1,400 people, most of them civilians in their homes, on the streets and at an outdoor rave party, and took 220 hostages in a surprise raid that Israeli Prime Minister Benjamin Netanyahu called the worst "since the Holocaust".

Israel has retaliated with relentless air strikes and an unfolding ground offensive that the Hamas-run health ministry in Gaza says has claimed more than 8,000 lives, most of them civilians.

Turkish state television has also scrapped the broadcast of concerts and other festivities because of the "alarming human tragedy in Gaza".

Erdogan's lifelong defence of Palestinian rights has turned him into a hero across swathes of the Muslim world.

He announced that 1.5 million people had come out for a pro-Palestinian rally in Istanbul on Saturday that ended up drowning out national television coverage of the centenary.

Erdogan accused the Israeli government of behaving like a "war criminal" and trying to "eradicate" Palestinians.

His remarks prompted Israel to announce the withdrawal of all diplomatic staff for a "re-evaluation" of relations.

A man stands wrapped in the national flag of Turkey outside Anitkabir, the mausoleum of the Turkish Republic's Founder Mustafa Kemal Ataturk, as people gather to mark the 100th anniversary of the Republic of Turkey in Ankara, on October 29, 2023. Turkey marked its centenary as a post-Ottoman republic on October 29, 2023, with somewhat muted celebrations held in the shadow of Israel's escalating war with Hamas militants in Gaza. (Photo by Adem ALTAN / AFP)

Turbulent spell

The emerging diplomatic crisis further pulled attention away from Turkey's birthday party and onto Erdogan's handling of global affairs.

Turkey has suffered a turbulent spell of relations with Western allies since Erdogan survived a failed coup attempt in 2016 that he blamed on a US-based Muslim preacher.

Some analysts saw Saturday's pro-Palestinian rally as part of Erdogan's tacit effort to undermine Ataturk's secular vision.

But one survey suggested that Erdogan's comments play to his Islamic conservative core of supporters and not the public at large.

The Metropoll survey showed just 11.3 percent of the respondents saying they "back Hamas" while more than half preferring to see Turkey either stay "neutral" or mediate.