Twitter CEO Jack Dorsey said Thursday that it should not have been possible for one of his employees to deactivate the president's Twitter account.

"We had an employee who, on this person's last day, took it upon themselves to deactivate the account," Dorsey said. "There are a number of things that came out of this for us. First, that should never have been possible. We started looking into the controls we have in place, what we can improve and where we have weaknesses, where we have gaps. Second, particular policies around what agents have control over and what they don't."

Dorsey spoke in an interview with New York Times columnist and CNBC anchor Andrew Ross Sorkin at The New York Times DealBook Conference. Sorkin asked if Dorsey received a call from the president's staff, and he said they've had "conversations."

President Donald Trump had his account deactivated for 11 minutes earlier this month, an action that's very different from an account suspension, according to Dorsey, but results in the account being out of public view.

Tweet: Earlier today @realdonaldtrump's account was inadvertently deactivated due to human error by a Twitter employee. The account was down for 11 minutes, and has since been restored. We are continuing to investigate and are taking steps to prevent this from happening again.

Dorsey said that Twitter has had to flex "new muscles" as far as transparency, especially when it comes to how and why accounts are blocked from the Twitter feed. He said there is a policy to keep content live based on whether it is "newsworthy," referring to the president's tweets.

"We're trying to close the gap between policy interpretation and policy enforcement," Dorsey said.

Twitter is under scrutiny for social media's role in spreading Russian propaganda during the 2016 election.

Sorkin asked Dorsey why he did not attend recent congressional hearings on the topic of Russian interference, sending a lawyer instead, just like Google and Facebook.

Dorsey said he would absolutely be happy to stand up and represent his company, but that the lawyer was the best person to speak to the deep nuances of Twitter's legal policies.

"If I was called specifically, I would go," Dorsey said. "I would get prepared and make sure I understood every single aspect of what happened and what we're doing about it, more importantly."

Twitter recently rolled out extended character limits of 280 characters for tweets. Dorsey said he still will likely average under 140.

Dorsey is one of the few people to take on the challenge of running two publicly traded companies, Twitter and Square. Both companies have performed well over the past few months.

Dorsey said it took time to understand how to run both companies, but he's learned that the right team and the right use of time are more important than how much time he spends at each company. He compared his ventures to the Walt Disney company in that he plans for his companies to endure beyond his lifetime, and that means building structures that do not depend solely on him. (Dorsey is a board member at Disney.)

Twitter reported higher-than-expected earnings for last quarter, despite a nearly flat user base. And Square also exceeded Wall Street's expectations, narrowing losses amid a growing volume of transactions. The company is also delving deeper into hardware with a new product called Square Register.

But the pressure is high on both companies to aim for perfection. Square shares have seen triple-digit percentage gains this year.

Dorsey said that Square lost some customers to aggressive competitors like Amazon, but many of them have come back.

Dorsey said that much of the commentary around financial innovations like bitcoin is very surface level, and that bitcoin research could have wide-ranging and "seminal" implications. Square briefly accepted bitcoin in 2014.

"It's a decentralized ledger. That has extreme power," Dorsey. "I want to make sure as a company — and this is not just Square, but also Twitter — that we're looking at technologies like the blockchain, like cryptocurrencies, and learning from it, and learning how to apply it."