President Donald Trump on Thursday signed an executive order that will give the Treasury Department the ability to crack down on individuals and entities that do business with North Korea.Before a working lunch with the leaders of South Korea and Japan -- U.S. allies who have been threatened repeatedly by the Kim-Jong Un regime -- the president announced the harsh sanctions in New York, where he and other world leaders have been meeting for the United Nations General Assembly.The order is aimed at cutting revenues that help the isolated communist nation in its mission to develop nuclear weapons."Foreign banks will face a clear choice: do business with the U.S. or facilitate trade with the lawless regime in North Korea," Trump said.CLICK HERE to read President Trump's new executive order on North Korea.The order also targets North Korea's shipping and trade networks by putting a 180-day ban on vessels and aircraft that have visited the country from visiting the U.S. It also targets vessels that have been in a ship-to-ship transfer with a vessel that has visited North Korea within 180 days.Along with the announcement, Trump said China's central bank has told other banks in the country to immediately stop doing business with North Korea. China, which has condemned the North's nuclear ambitions, is the nation's closest ally."We call on all countries around the world to join us by cutting off all trade and financial tied to North Korea," Treasury Secretary Steve Mnuchin said Thursday afternoon.The sanctions were issued two days after Trump threatened the destruction of North Korea if it continues provoking U.S. allies. In an address to the General Assembly on Tuesday, Trump insulted North Korean leader Kim-Jong Un, saying "Rocket Man is on a suicide mission.""The United States has great strength and patience," he said, "but if it is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea."Late Wednesday, North Korea's foreign minister responded to the threat by comparing Trump's comments to a "barking dog."North Korea has responded to past sanctions with missile tests and threats of war. At the beginning of September, it conducted its sixth and largest nuclear test yet, drawing wide condemnation from the international community.Even after the sanctions and ever-rising rhetoric, when asked if there is still an opportunity for dialogue between the nations, Trump said "Why not?"