U.S. Sen. Rand Paul, R-Ky., formally kicked off his campaign for president Tuesday in his home state, where he railed against the "Washington machine" and promised "a return to prosperity" and "a government restrained by the constitution." Running as a Washington outsider despite serving four years in the Senate, Paul also slammed both political parties for threatening the country's economy and security.

"I have a message, a message that is loud and clear that does not mince words: We have come to take our country back," Paul said from the Galt House Hotel in Louisville. "Today I announce with God's help, with the help of liberty lovers everywhere, that I am putting myself forward as a candidate for president of the United States of America."

Paul said "opportunity and hope are slipping away for our sons and daughters," adding that Democrats and Republicans are both responsible. "It seems to me that both political parties and the entire political system are to blame," he said. "Big government and debt doubled under a Republican administration and is now tripling under Barack Obama's watch."

Calling Washington "horribly broken," Paul said, if elected president, he would press for a balanced budget amendment to force the federal government to spend only as much as it takes in. "Congress will never balance the budget unless you force them to do so," he said. "Congress has an abysmal record at balancing anything."

Turning to foreign policy, Paul took a swipe at Obama for his reluctance to say groups like the Islamic State are Muslim extremists. "Without question, we must defend ourselves and American interests from our enemies, and until we name that enemy, we can't win the war," he said. "The enemy is radical Islam -- you can't get around it."

Paul also said the U.S. needs to rein in foreign aid. "We do not project strength by borrowing money from China to send it to Pakistan," he said. "Let's quit building bridges in foreign countries and use that money to build some bridges here at home."

As a libertarian, Paul has been outspoken on civil liberties. He said warrantless searches of Americans' phones and computer records are "un-American and a threat to our civil liberties," adding that he would end "unconstitutional surveillance" if elected president. "I say phone records of law-abiding citizens are none of their damn business," he said, referring to the country's intelligence agencies.

While the speech was the formal kickoff to Paul’s campaign, the Kentucky senator announced his presidential run on his website shortly before his address. “I am running for president to return our country to the principles of liberty and limited government,” he wrote.

Paul, an ophthalmologist, is the son of Ron Paul, the former Texas congressman and a three-time presidential candidate. While Ron Paul didn’t win the nomination, his runs in 2004 and 2008 galvanized grassroots supporters, many of them young people who didn’t traditionally support Republican candidates.