In addition to the two troops, whose military service was not identified, one Defense Department civilian and one American contractor supporting defense operations were killed, officials with U.S. Central Command announced.
This has been continuously contradicted, however, by figures such as National Security Advisor John Bolton and Special Envoy for Syria James Jeffrey, who say the US mission includes goals such as the withdrawal of all Iranian forces from Syria and guaranteed protections for the Kurds.
Vice-President Mike Pence repeated the claim shortly after the USA military announced the latest deaths, saying the "caliphate has crumbled" and the militant network "has been defeated".
They also said surveillance video from a nearby building showed a lone attacker rushing into a crowd near a restaurant where USA troops were known to meet with their coalition counterparts.
However, Anadolu said that the safe zone will include Syria's locations to the north of Raqqa and others to the north of a-Hasakah, passing through Sarrin, the north Ayn Issa, Suluk, Ras al-Ayn, the north of Tell Tamer, Darbasiya, Amuda, Qamishli, Wardiyah, Tell Hamis, Al-Qahtaniyah, Al-Yarubiyah and Al-Malikiyah.
Erdogan said that five of the victims were American, however. Several cars were also damaged. Debris and blood covered the street.
Critics have said a pullout was premature, that IS was still not defeated and a withdrawal could lead to a power vacuum that would fuel even more violence.
His decision led to the resignation of US Defence Secretary Jim Mattis, who cited policy differences with the president for his leaving.
As the crowd cheered, Pence declared "We are bringing our troops home".
Prince Harry and Meghan Markle will attend Cirque du Solei in London
Meghan rescued her dog Guy from a shelter in 2015 and she and Harry are believed to have adopted a second pup previous year . The Duchess is a proud dog lover, having previously supported various animal rescue centres in her home city of Los Angeles.
The rare attack came days after the USA began the process of withdrawing from Syria, pulling out equipment from the northeast into neighboring Iraq. No troops are known to have withdrawn yet.
Its leadership remains at large and it still holds a handful of towns and villages in eastern Syria. President Trump has claimed (on Twitter and elsewhere) that the only task of US forces in Syria is the defeat of the Islamic State.
The attack, which occurred near midday, targeted USA troops conducting patrols around the city, which remains under the control of the YPG/PKK terrorist group.
The president's declaration surprised allies and foes alike, drawing consternation from global partners and accusations of abandonment from a US -backed Kurdish force that has suffered thousands of casualties during the military campaign.
The crowded terrain has become more combustible as Turkey threatens to attack Kurdish-run towns further east. Operating from a half-dozen bases in the northeast part of the country, American advisers have steadily built up the Syrian partners by training and arming them.
The Britain-based Syrian Observatory for Human Rights, a Syrian war monitoring group, and a local town council said Wednesday that the explosion took place near a patrol of the US -led coalition and that there are casualties.
In a series of tweets Sunday, Trump suggested the creation of a buffer zone in northern Syria to protect the mixed Syrian Kurdish and Arab SDF from threatened attack by Turkey.
It was unclear what impact the blast might have on Trump's plans after he confounded his own national security team with a surprise decision last month to withdraw all 2,000 USA troops from Syria, declaring Islamic State had been defeated there.
Americans injured in the bombing have been evacuated from the scene by helicopter, with images from the city showing a restaurant devastated by the blast.
"It raises the question of how Manbij would fare absent the current US force posture, given recent proposals for Turkey to establish a safe-zone in the region", he said.