"As soon as I take office, I will ask Congress to fully eliminate the defense sequester and will submit a new budget to rebuild our military," Trump told the Union League of Philadelphia in a speech focused on U.S. military readiness. "It is so depleted. We will rebuild our military."
The so-called military sequester was a part of the 2011 Budget Control Act, which mandated $500 billion be cut from the military over the decade.
The Republican presidential nominee also used the opportunity today to attack his Democratic rival, Hillary Clinton.
"She's trigger happy and very unstable. Whether we like it or not, that's what's going on," he said.
He invoked the controversy surrounding Clinton's emails after a release of FBI documents last week showing that she told the FBI that she did not recall receiving any emails that should not have been on an unclassified server.
"Hillary Clinton has taught us, really, how vulnerable we are in cyberhacking," Trump said. "That is probably the only thing that we've learned from Hillary Clinton.
"Which is why, one of the first things we must do is to enforce all classification rules and to enforce all laws relating to the handling of classified information."
FBI Director James Comey has said that three email chains that included Clinton contained at least one paragraph marked "(C)," indicating the paragraph contained confidential material.
Trump promised more funds would go to the military, vowing to build an Army of 540,000 troops, a Marine Corps based on 36 battalions, a Navy of 350 ships and an Air Force of 1,200 fighter aircraft.
And in a rare moment of specificity, the normally vague Trump also revealed how he would fund his increased spending: in part "through responsible workforce attrition," the end of "funding programs that are not authorized in law" and a request that other member nations fulfill their financial obligations to NATO.
"They understand it. They know they have to do it. They can afford to do it. They have no respect for our leadership. They have no respect for our country," he said.
"They will do it. They will be happy to do it. They will be happy to do it," he continued.
Trump has long been an advocate of increasing military spending, although he had been circumspect in detailing how to pay for it.
Throughout his speech today, the New York real estate developer spoke of his goal to have people in his administration develop plans, declaring that within the first month of his presidency, he would ask his generals for a plan to defeat ISIS and ask others for a plan to combat cyberespionage.
After sidestepping when asked Tuesday whether he would advocate for regime change in Syria, he took a stance today, advocating for Syrian President Bashar al-Assad to stay in power.
"In a Trump administration, our actions in the Middle East would be tempered by realism," Trump said. "The current strategy of toppling regimes with no plan for what to do the day after only produces power vacuums that are filled simply by terrorists. Gradual reform, no sudden and radical change should be our guiding objective in that region.
"We should work with any country that shares our goal of destroying ISIS and defeating radical Islamic terrorism," he said.
He also alluded, as he has before, to strengthening the U.S.-Russia relationship. "And we are going to form new friendships and partnerships based on this mission and this mission alone," he said.
Policy addresses are becoming more commonplace for Trump, who once said he wanted to avoid revealing policy details for fear of tipping off Democrats or U.S. enemies.