Arab League

Hossam Zaki, deputy secretary-general of the Arab League said that foreign ministers from around the region will be meeting in Cairo on Saturday to discuss Turkey's military operation.

Ahmed Aboul Gheit, head of the pan-Arab organisation said that Turkey's incursion is a "blatant violation of Syria's sovereignty and threatens Syria's integrity".

He added that Turkey's incursion also threatens to inflame further conflicts in eastern and northern Syria, and "could allow for the revival" of ISIL.

Egypt

Egypt's foreign ministry condemned the offensive as "a blatant and unacceptable attack on the sovereignty of a brotherly Arab state". It called for an emergency meeting of the League of Arab States.

Saudi Arabia

Saudi Arabia said the offensive would undermine the region's security and the battle against ISIL.

The Turkish army's "aggression" would have "negative repercussions on the security and stability of the region", the foreign ministry said on Twitter.

It would also "undermine international efforts to fight the Islamic State terrorist group".

Syria

Syria's Foreign Ministry condemned Turkey's plans, calling it a "blatant violation" of international law and vowing to repel an incursion.

Iraq

Iraqi President Barham Salih called Turkey's "incursion" a "grave escalation" on Twitter.

"[It] will cause untold humanitarian suffering, empower terrorist  groups. The world must unite to avert a catastrophe, promote political resolution to the rights of all Syrians, including Kurds, to peace, dignity and security," Salih said.

UAE

In a statement, the UAE foreign ministry said that the aggression represents a dangerous development and a blatant and unacceptable aggression against the sovereignty of an Arab state in contravention of the rules of international law.

Bahrain

The Bahrain foreign ministry condemned the offensive according to state news agency BNA.

The statement said Bahrain supports the call for an emergency meeting of the Arab League Council to take a unified Arab stand towards the aggression.

Kuwait

Kuwait said on Wednesday that the Turkish offensive in northeast Syria is a direct threat to stability and peace in the region and called for restraint, the state news agency reported.

United States

US President Donald Trump said Turkey's air assault was "a bad idea" not backed by the United States, and called on Ankara to protect religious minorities.

"The United States does not endorse this attack and has made it clear to Turkey that this operation is a bad idea," Trump said in a statement released by the White House.

"Turkey has committed to protecting civilians, protecting religious minorities, including Christians, and ensuring no humanitarian crisis takes place - and we will hold them to this commitment."

Russia

Before the launch of the offensive, Russian President Vladimir Putin urged Erdogan to "think carefully" before taking any action.

"Putin called on his Turkish partners to think carefully about the situation so as not to harm overall efforts to resolve the Syrian crisis," the presidency said following a phone call between the two leaders.

UK

British Foreign Secretary Dominic Raab said in a statement he had "serious concerns about the unilateral military action that Turkey has taken".

"This risks destabilising the region, exacerbating humanitarian suffering, and undermining the progress made against Daesh which should be our collective focus."

Germany

German Foreign Minister Heiko Maas said Turkey's operation would lead to further destabilisation of the region and could strengthen ISIL. He urged Turkey to end the operation.

France

French Foreign Minister Jean-Yves Le Drian said on his Twitter feed that the operation "is jeopardising the anti-Islamic State coalition's security and humanitarian efforts and is a risk for the security of Europeans. It has to end."

French Defence Minister Florence Parly said that the Turkish offensive is dangerous and should stop.

"[It is] dangerous for the security of the Kurds. Dangerous because it benefits Islamic State, which we have been fighting for five years. It must stop," Parly wrote on Twitter.

Italy

Italian Prime Minister Giuseppe Conte said the operation risked destabilising the region and harming civilians.

Netherlands

Dutch Foreign Minister Stef Blok said he has summoned the Turkish ambassador.

"I call on Turkey not to follow the path it has chosen," Blok said on Twitter. "No one can benefit from the potentially terrible humanitarian consequences. The operation can trigger new refugee flows and harm the fight against IS and stability in the region."

Denmark

Danish Foreign Minister Jeppe Kofod tweeted: "Deeply concerned about Turkish military operation in Syria.

In my view, this is a regrettable and wrong decision, which can have serious consequences for civilians and the fight against ISIL. Turkey must show restraint. Denmark is in close contact with allies on the matter."

Australia

Australian Prime Minister Scott Morrison said on Thursday he had been in contact with the governments of Turkey and the US and was worried about the situation, and the risk of further instability in the area.

"We are very concerned about what this could potentially mean for the Kurdish people," Morrison said. "We're concerned about what this could mean for the potential for the resurgence of Daesh," he added, using the Arabic acronym for the Islamic State group.