ABC News' Jon Karl interviewing Donald Trump attorney Jay Sekulow. ABC

President Donald Trump's lawyer told ABC News on Sunday morning that Donald Trump Jr.'s meeting last June with Russian lawyer Natalia Veselnitskaya and Russian-American lobbyist Rinat Akhmetshin was innocent because if it weren't, the Secret Service would not have "allowed these people in."

"I wonder why the Secret Service — if this was nefarious — why the Secret Service allowed these people in?" Sekulow told ABC News' Jon Karl. "The president had Secret Service protection at that point, and that raised a question with me."

It is unclear why Sekulow seemed to assume the Secret Service vetted people Trump Jr. met with. The Secret Service confirmed on Sunday that Trump Jr. was not under its protection on June 9, 2016, and said it "would not have screened anyone he was meeting with at that time." Trump's campaign chairman at the time, Paul Manafort, and his son-in-law, Jared Kushner, were not under Secret Service protection at that point either, as Think Progress noted on Sunday.

The Secret Service would not have had to do a background check on the attendees beforehand — only a physical screening — since Trump was just a candidate at the time, former Secret Service agent Jonathan Wackrow told CNN on Sunday.

Indeed, Akhmetshin told Yahoo that "no one asked us for ID's" when he and Veselnitskaya entered Trump Tower. "We literally walked in," he said. He told The Washington Post in an earlier interview that Veselnitskaya invited him to the meeting only on the day it took place.

Sekulow's comments about the Secret Service garnered widespread attention, raising questions about whether Trump himself was present at the meeting he said he learned about only last week. Trump Jr. on Tuesday released emails indicating he was offered dirt on Hillary Clinton by someone described as a "Russian government attorney" who wanted to meet with him to discuss it further. Trump Jr. agreed to the meeting, replying, "I love it."

According to media reports from that time, Trump was at Trump Tower at 4 p.m. while the meeting was taking place in his son's office. The only public event the then-candidate attended that day was a fund-raising lunch for the Trump Victory Fund, CNN reported, and he was back at Trump Tower by 1 p.m.

Akhmetshin, a Russian-born lobbyist who since at least last year has been working with the lawyer, Veselnitskaya, to try to overturn a US law sanctioning Russians, confirmed his participation in the meeting to the Associated Press on Friday. He said that Trump Jr. asked Veselnitskaya for information on illicit money flowing into the Democratic National Committee but that Veselnitskaya had nothing substantive to provide.

In a later interview with Yahoo, however, Akhmetshin said Veselnitskaya left documents with Trump Jr. at his office. Akhmetshin said he thought the documents related to the alleged money flow but he couldn't be sure because he "didn't prepare the document."

Trump with his eldest son, Donald Trump Jr. Saul Loeb-Pool/Getty Images

The meeting lasted "15 to 20 minutes," according to Sekulow. Trump Jr. had said it lasted about half an hour. Either way, at 4:40, roughly 40 minutes after the meeting began, Trump began tweeting about Clinton's emails.

"Where are your 33,000 emails that you deleted?" Trump tweeted in response to a quip from Clinton.

Trump and his surrogates have insisted the president did not learn of the meeting until last week. But his legal team knew about it at least three weeks ago, according to Yahoo, when Jared Kushner's lawyers informed them of the email chain. The chain, which was forwarded to Kushner, prompted him to amend his security-clearance form — for the second time — on June 21.

Trump Jr. has said the meeting was inconsequential and a waste of time. But Sekulow's comment about the Secret Service, and Trump's reported presence at Trump Tower while the meeting was taking place, raise questions about how plausible it is that his son, campaign manager, son-in-law, and Secret Service detail (if they were made aware of the rendezvous) never told him about it or that he did not attend.

That is especially true given Trump's hands-on approach to all aspects of his business empire, biographer Tim O'Brien has noted. According to a former business associate, Jody Kriss, "Donald [Sr.] was always in charge."

"Donald had to agree to every term of every deal and had to sign off on everything," Kriss, who worked with the real-estate company Bayrock before leaving because he was convinced it was a money-laundering front, told O'Brien last month. "Nothing happened unless he said it was OK to do it. Even if Donald Jr. shook your hand on a deal, he came back downstairs to renegotiate if his father told him to."

This story has been updated.