"Well, I wonder why the Secret Service, if this was nefarious, why the Secret Service allowed these people in," Jay Sekulow said on ABC's "This Week.
" "The President had Secret Service protection at that point, and that raised a question with me."
After Sekulow's comments aired, the Secret Service responded that it wouldn't have checked out the participants of the meeting because Trump's eldest son wasn't in their charge.
"Donald Trump Jr. was not a protectee of the USSS in June, 2016," the agency told CNN in a statement. "Thus we would not have screened anyone he was meeting with at that time."
The meeting, which took place in Trump Tower in New York City, involved
Trump Jr., Trump's son-in-law Jared Kushner, then-campaign chairman Paul Manafort, Russian lawyer Natalia Veselnitskaya, publicist Rob Goldstone, Russian-American lobbyist Rinat Akhmetshin and at least two other people, sources familiar with the meeting told CNN.
The meeting has drawn widespread scrutiny since The New York Times reported on it last weekend. In the wake of the Times' reporting, Trump Jr. posted a series of emails on Twitter between himself and Goldstone, an acquaintance who pointed to the Russia attorney as the source of potentially damaging information on Hillary Clinton as "part of Russia and its government's support for Mr. Trump."
The President has maintained having no knowledge of the meeting until the Times' reporting.
Sekulow reiterated Sunday on CNN's "State of the Union" that Trump did not know about the meeting, saying: "The President was not engaged in this, was not aware of it."
That assertion raised skepticism
from Sen. Mark Warner, the top Democrat on the Senate intelligence committee, later in the same program.
"Frankly, it's a little bit unbelievable that neither the son or the son-in-law ever shared that information with their dad, the candidate," Warner said.
The Virginia senator went on to say he wants to question everyone involved in the meeting as part of the committee's investigation into Russian interference in the 2016 election.
"Whether we'll be able to get the Russian nationals to come over and testify is an open question," Warner said. "Those people that our committee has jurisdiction over, the Americans, I sure as heck want to talk to them."