"We strongly condemn [the] Turkish offensive in Northeast Syria.
Turkey risks further destabilization of the region & ISIS resurgence," read a statement, released just hours after reports began to emerge that the attack was underway.
"We call on Turkey to end the offensive and pursue its security interests peacefully."
The United Nations Security Council is set to meet on Thursday in response to the attack, international diplomats announced later in the day. According to Amelie de Montchalin, the French Minister of European Affairs, Britain, France, and Germany called for the meeting shortly after the launch of the operation on Wednesday evening.
Read More: UN Security Council to hold emergency meeting Thursday after Turkey’s military action: diplomats
A White House statement made late on Sunday explained that American forces would withdraw from areas in northern Syria where Turkey has said it would launch a long-threatened military operation targeting US-backed Kurdish forces.
The move drew stern bipartisan criticism of President Donald Trump.
Read More: Trump waffles amid continued criticism, as Turkish attack looms
On Wednesday afternoon, Turkish warplanes and artillery began shelling Syria's predominantly Kurdish northeastern town of Serekaniye.
Read More: Turkish warplanes start shelling northeast Syria, SDF spokesperson says
A source in Serekaniye told Kurdistan 24 that four warplanes were hovering over the town and that heavy artillery had been fired at surrounding areas.
According to local media, Turkish warplanes have bombarded Safeh village, located five kilometers on the western outskirts of Serekaniye.
It added that Turkish artillery shelled the main streets of Mahatta and Malla Darwish in the town.
Additional reports have claimed that Turkish warplanes began bombarding Ain Issa, north of Raqqa, as well as shelling in the town of Tal Abyad.
Local media said that Turkish artillery had struck silos in the eastern outskirts of Qamishli.
Waves of people have started to leave their homes to flee the Turkish shelling, including some that have fled to the Kurdistan Region.
Read More: More Iraqi refugees return from Turkey through Kurdistan border
In late May, Maas previously confirmed that Germany supported a US plan to establish a security zone in northeastern Syria along the Turkish border to help maintain stability there, after the drawdown of US forces, which have been working with the Kurdish-led Syrian Democratic Forces (SDF) to defeat the Islamic State.
Related Article: Germany backs US plans for safe zone in Syria
"We strongly welcome—we very much welcome—the fact that the United States has decided to continue its presence on the ground" in northeast Syria, he said during a joint appearance with US Secretary of State Mike Pompeo in Berlin.