President Obama spoke to the nation about the Syria situation on Tuesday night. (Wikimedia Commons/Creative Commons)

President Obama addressed the Syria chemical weapons crisis Tuesday in a national address, summarizing statistics from the "brutal civil war" and described the United States' role in the international community.

The president said "the situation profoundly changed" after the Aug. 21 chemical weapons attack. Obama went on to describe images of Syrian victims suffering from chemical weapons, images used to point to why chemical weapons are illegal.

"On Aug. 21, these basic rules were violated…the world saw thousands of videos…from the attack…moreover, we know the Assad regime was responsible," the president said. He added that rockets were fired into areas where rebels gathered and the weapons took effect after the rockets landed.

He said tests conducted on blood and hair confirmed chemical weapons were used. He proposed the question to the nation: How should the U.S. act?

Obama said if the U.S. failed to act, the Assad regime would not stop, other groups would obtain weapons, weapons that could be used against U.S. allies if the war moved across the border. It would also weaken the ban on other illegal weapons, he argued.

"I believed it was right…to take this debate to Congress," he said. 

Obama said that he knew the decision to get involved would not be popular.

In response to criticisms, President Obama said, "I will not put American boots on the ground in Syria."

Obama said the threat caused Assad to think twice and forced the regime to admit to using chemical weapons and accept Russia's proposal in relinquishing its stockpile.

Obama specifically asked people to watch the video of Syrians being harmed by chemical weapons and asked how they could justify not acting. He also said the United States needed to act, so leaders around the world would know the international community was committed to ensuring deadly weapons, such as sarin gas, will never be used again.

The president said Secretary of State John Kerry would meet with Russian Minister of Foreign Affairs Sergey Viktorovich Lavrov on Thursday.

CNN's John King reported before the president took the podium that the permanent members of the U.N. Security Council - China, France, Russia, the United Kingdom and the United States - would meet on Wednesday. 

Tuesday night's speech came after a day of meetings with Democratic and Republican senators on Capitol Hill. According to pool reports, Obama met with members of the Democratic Caucus for one hour and twenty-five minutes and with members of the Republican Conference for about one hour and ten minutes. 

The president also spoke Tuesday with French President Francoisçois Hollande and British Prime Minster David Cameron, the White House stated. A readout provided by the White House said, "They agreed to work closely together, and in consultation with Russia and China, to explore seriously the viability of the Russian proposal to put all Syrian chemical weapons and related materials fully under international control in order to ensure their verifiable and enforceable destruction. These efforts will begin today at the United Nations, and will include a discussion on elements of a potential UN Security Council Resolution."

Reach Associate News Editor Max Schwartz here; follow him on Twitter here.