WASHINGTON — President Obama on Thursday vetoed a $612 billion defense policy bill, rejecting a broadly supported measure that sets funding for military salaries and equipment, and intensifying his struggle with the Republican-led Congress over federal spending.

Mr. Obama has wielded the veto only four other times since taking office in 2009, and his fifth one Thursday signaled his determination to use the defense bill as a bargaining chip to push Republicans to abandon strict spending limits on military and domestic programs enacted in the 2011 Budget Control Act.

In an Oval Office ceremony choreographed for the news media, Mr. Obama signed his veto message, saying that while the legislation had a number of positive attributes, it fell “woefully short” in key areas that Congress had an obligation to address.

“My message to them is very simple: Let’s do this right,” Mr. Obama told reporters while seated at his desk. “We’re in the midst of budget discussions. Let’s have a budget that properly funds our national security as well as economic security. Let’s make sure that we’re able in a constructive way to reform our military spending to make it sustainable over the long term.”