obama (syria presser)*President Barack Obama, seemingly between a rock and a hard place, as far as a strike against Syria is concerned, will address the country Tuesday to make his case.

Obama made the announcement Friday at a press conference before leaving a summit of the Group of 20 world powers in Russia. He said that Syria’s use of chemical weapons “isn’t just a Syrian tragedy. It’s a threat to global peace and security.”

Obama cast military action in Syria as critical to upholding the world’s prohibition on chemical weapons.

“I want people to understand that gassing innocent people, delivering chemical weapons against children, is not something we do,” the president said. “It’s prohibited in active wars between countries. We certainly don’t do it against kids.”

The United States says that Assad, more than two years into a civil war, gassed 1,400 people to death, including more than 400 children, in a rebel-controlled neighborhood Aug. 21.

“Obviously, my preference would be against to act internationally, in a serious way, and to make sure that Mr. Assad gets the message,” Obama said. “I’m not itching for military action.”

Obama said that he would tell Congress and the public in coming days that any American strike would be “limited and proportionate.” He did not directly answer a question about whether he would go forward with an attack without the approval of Congress.

Military officials on Friday told NBC News that the White House asked the Pentagon for an expanded list of potential targets in Syria, and one senior official warned that it could represent “mission creep.” Asked about the report in St. Petersburg, Obama called it “inaccurate” and declined to elaborate.

Read/learn MORE at NBC News.

Watch the president address the issue from his press conference this morning:

Visit NBCNews.com for breaking news, world news, and news about the economy