WASHINGTON (AP) -- President Donald Trump on Sunday defended his use of the phrase "Mission Accomplished" to describe a U.S.-led missile attack on Syria's chemical weapons program, even as his aides stressed continuing U.S. troop involvement and plans for new economic sanctions against Russia for enabling the regime of Bashar Assad.
Stepping up the pressure on Syria's president, U.S. Ambassador to the United Nations Nikki Haley indicated the sanctions to be announced Monday would be aimed at sending a message to Russia, which she said has blocked six attempts by the U.N. Security Council to make it easier to investigate the use of chemical weapons.
"Everyone is going to feel it at this point," Haley said, warning of consequences for Assad's foreign allies.
"The international community will not allow chemical weapons to come back into our everyday life," she said. "The fact he was making this more normal and that Russia was covering this up, all that has got to stop."
In an early-morning tweet, Trump said the strike was "perfectly carried out" and that "the only way the Fake News Media could demean was by my use of the term "Mission Accomplished." He added that he knew the media would "seize" on the phrase, but said it should be used often. "It is such a great Military term, it should be brought back," he wrote.
Trump tweeted "Mission Accomplished" on Saturday after U.S., French and British warplanes and ships launched more than 100 missiles nearly unopposed by Syrian air defenses. While he declared success, the Pentagon said the pummeling of three chemical-related facilities left enough others intact to enable the Assad government to use banned weapons against civilians if it chooses.
His choice of words recalled a similar claim associated with President George W. Bush following the U.S.-led invasion of Iraq. Bush addressed sailors aboard a Navy ship in May 2003 alongside a "Mission Accomplished" banner, just weeks before it became apparent that Iraqis had organized an insurgency that would tie down U.S. forces for years.
On Sunday, Haley made clear the United States won't be pulling troops out of Syria right away, saying U.S. involvement there "is not done."
Haley said the three U.S. goals for accomplishing its mission are making sure chemical weapons are not used in a way that could harm U.S. national interests; that the Islamic State group is defeated; and that there is a good vantage point to watch what Iran is doing.
"We're not going to leave until we know we've accomplished those things," she said.
Haley said the joint military strike "put a heavy blow into their chemical weapons program, setting them back years" and reiterated that if Assad uses poison gas again, "the United States is locked and loaded."
The nighttime assault was carefully limited to minimize civilian casualties and avoid direct conflict with Russia in Syria, but confusion arose over the extent to which Washington warned Moscow in advance. The Pentagon said it gave no explicit warning. The U.S. ambassador in Moscow, John Huntsman, said in a video, "Before we took action, the United States communicated with" Russia to "reduce the danger of any Russian or civilian casualties."
Russia has military forces, including air defenses, in several areas of Syria to support Assad in his long war against anti-government rebels.
Russia and Iran called the use of force by the United States and its French and British allies a "military crime" and "act of aggression." The U.N. Security Council met to debate the strikes, but rejected a Russian resolution calling for condemnation of the "aggression" by the three Western allies.
Assad denies he has used chemical weapons, and the Trump administration has yet to present hard evidence of what it says precipitated the allied missiles attack: a chlorine gas attack on civilians in Douma on April 7. The U.S. says it suspects that sarin gas also was used.
"Good souls will not be humiliated," Assad tweeted, while hundreds of Syrians gathered in Damascus, the capital, where they flashed victory signs and waved flags in scenes of defiance after the early morning barrage.
The strikes "successfully hit every target," said Dana W. White, the chief Pentagon spokeswoman. The military said there were three targets: the Barzah chemical weapons research and development site in the Damascus area, a chemical weapons storage facility near Homs and a chemical weapons "bunker" a few miles from the second target.
Although officials said the singular target was Assad's chemical weapons capability, his air force, including helicopters he allegedly has used to drop chemical weapons on civilians, were spared. In a U.S. military action a year ago in response to a sarin gas attack, the Pentagon said missiles took out nearly 20 percent of the Syrian air force.
The U.S.-led operation won broad Western support. The NATO alliance gave its full backing; NATO Secretary-General Jens Stoltenberg said in Brussels that the attack was about ensuring that chemical weapons cannot be used with impunity.
In his televised address from the White House on Friday evening, Trump said the U.S. was prepared to keep up the economic, diplomatic and military pressure on Assad until he ends what Trump called a criminal pattern of killing his own people with internationally banned chemical weapons. That did not mean military strikes would continue. In fact, Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, said no additional attacks were planned.
Asked about Trump's "Mission Accomplished" assertion, White said it pointed to the successful targeting of three Syrian chemical weapons sites. What happens next, she said, is up to Assad and to his Russian and Iranian allies.
Marine Lt. Gen. Kenneth F. McKenzie, director of the Joint Staff at the Pentagon, said the allied airstrikes "took out the heart" of Assad's chemical weapons arsenal. He said the missiles hit the "sweet spot," doing the expected level of damage while minimizing the unintentional release of toxic fumes that could be harmful to nearby civilians.
But when pressed, he acknowledged that some unspecified portion of Assad's chemical arms infrastructure was not targeted.
"There is still a residual element of the Syrian program that is out there," McKenzie said.
Haley appeared on "Fox News Sunday" and CBS' "Face the Nation."