Uber has become increasingly reliant on food delivery during the pandemic. Reuters The DOJ is taking a closer look at Uber's plans to buy Postmates, Uber disclosed in a regulatory filing Friday. The "second request," as it's called, puts the deal on hold indefinitely until both companies "substantially comply" with the government's request for more details and it gives the deal a green light. But the DOJ's request signals it's "concerned about the deal," Sam Weinstein, a former DOJ antitrust lawyer, told Business Insider. Uber pivoted to buy Postmates after merger talks with Grubhub reportedly fell through over similar antitrust concerns as the platform faces increased scrutiny from lawmakers. Visit Business Insider's homepage for more stories. Uber's plans to expand its food delivery business by acquiring Postmates have hit a roadblock.In a regulatory filing Friday, Uber disclosed that the US Department of Justice has issued a "second request" to both companies, temporarily halting the deal while the government gathers more information.Under antitrust laws, companies must wait, typically 30 days, to close a potential deal after informing the government of their plans.