The Pentagon said on Friday that 34 United States service members had been diagnosed with traumatic brain injury following missile attacks by Iran on a base in Iraq earlier this month.
Trump and other top officials initially said Iran's attack had not killed or injured any US service members.
Last week the US military said 11 US troops had been treated for concussion symptoms after the attack on the Ain al-Assad airbase in western Iraq and this week said additional troops had been moved out of Iraq for potential injuries.
The January 8 attack was retaliation for a US drone strike in Baghdad on January 3 that killed Qassem Soleimani, the commander of the elite Quds Force of Iran's Islamic Revolutionary Guard Corps (IRGC).
Pentagon spokesman Jonathan Hoffman told reporters on Friday that eight service members who had been previously transported to Germany had been moved to the US. Hoffman said the service members were transported earlier on Friday and would receive treatment at either Walter Reed military hospital or their home bases.
Nine service members remain in Germany and are undergoing evaluations and treatment.
On Wednesday, Trump appeared to play down the injuries, saying he "heard that they had headaches and a couple of other things".
Pentagon officials have said there had been no effort to minimise or delay information on concussive injuries, but its handling of the injuries following Tehran's attack has renewed questions over the US military's policy regarding how it deals with suspected brain injuries.
As thousands of Iraqis headed to an upscale Baghdad neighbourhood, heeding influential Shia cleric Muqtada al-Sadr's calls to participate in a million-man march, they had to contend with road closures and a heavier than usual security presence.
Sadr, head of Sairoon, the largest coalition bloc in parliament, has capitalised on rising regional tensions, which soared after the United States assassinated Iranian military general Qassem Soleimani on Iraqi soil.The January 3 US military drone strike also killed Abu Mahdi al-Muhandis, an Iraqi commander of the pro-Iranian Hashd al-Shabi militias (also called the Popular Mobilisation Forces or PMF).
As calls for an end to interference grew louder, the Iraqi parliament on January 5 backed a nonbinding resolution for all foreign troops - including 5,200 US soldiers - to leave the country.
Those calls were renewed at Friday's rally at Jadriya, a neighbourhood where politicians live and work.
"Today's protest is a referendum called for by the Iraqi people who consider the presence of US forces within the country a danger to them and to the region," civil servant Asad al-Hashemi told Al Jazeera.
"The US is the reason for the corruption and all of our misfortunes."
He said the US presence stokes dissent and increases the likelihood of people "acting out against it on our terrain, thus turning Iraq into an ongoing battlefield for competing geopolitical interests.
"We want to reclaim our sovereignty back."
