President Obama said Tuesday he believes Congress will vote to authorize military action against Syria over the use of chemical weapons, and he won the support of the top two Republicans in the U.S. House.
House Speaker John Boehner, R-Ohio, said after a White House meeting that he supports the president's "call for action" against Syria, and he believes most other congressional Republicans will do so as well.
"The use of chemical weapons is a barbarous act," Boehner said. "The use of these weapons has to be responded to."
House Majority Leader Eric Cantor, R-Va., also endorsed military action, saying that the United States has "a compelling national security interest to prevent and respond to the use of weapons of mass destruction, especially by a terrorist state such as Syria."
Cantor also said he hopes Obama uses force "judiciously," and maintains "consultation with the Congress."
Before the meeting with Boehner, Cantor and other members of Congress from both parties, Obama told reporters: "We have high confidence that Syria used - in an indiscriminate fashion - chemical weapons that killed thousands of people, including over 400 children."
Obama also said he is willing to work with lawmakers on the wording of a resolution authorizing the use of force as long as it preserves the mission of sending "a clear message" to the government of Bashar Assad, "degrading his capabilities to use chemical weapons, not just now but also in the future."
Some members of Congress said the resolution proposed by the White House is too open-ended on the use of force.
Congressional Democrats who met with Obama said they also support military action against Syria.
A congressional vote could be close. Some lawmakers have said the United States should not get involved in Syria; others question whether the administration has proved that Assad's government fired chemical weapons at Syrian rebels.
After the announcements by Boehner and Cantor, Rep. Justin Amash, R-Mich., tweeted that his constituents have expressed "almost unanimous opposition to U.S. strikes."
Boehner did not say he would pressure fellow Republicans into supporting action against Syria. His spokesman, Brendan Buck, said these will be "conscience votes" for lawmakers, and that the White House must lead the lobbying effort. "Everyone understands that it is an uphill battle to pass a resolution, and the Speaker expects the White House to provide answers to members' questions," Buck said.
Syria has denied using chemical weapons, attributing an attack Aug. 21 to the rebels themselves.
Asked if he was confident about upcoming votes in the House and Senate, Obama said: "I am."
Obama stressed that he envisions a "limited" and "proportional" mission designed to "degrade" Assad's chemical weapons capability.
There will be no U.S. troops on the ground in Syria, Obama said: "This is not Iraq and this is not Afghanistan."
The use of chemical weapons violates "international norms" and increases the possibility that terrorists could obtain such weapons, Obama said.
"That poses a serious national security threat to the United States and to the region and, as a consequence, Assad and Syria need to be held accountable," Obama said.
House Minority Leader Nancy Pelosi, D-Calif., said she is persuaded by the evidence against Assad, and that he "crossed a line" through the use of illegal chemical weapons.
The White House meeting featured a variety of congressional leaders, including Boehner and Senate Minority Leader Mitch McConnell, R-Ky., the top Republican in the Senate. Members of the Armed Services and Foreign Affairs Committees also attended the conference in the Cabinet Room.
McConnell did not comment directly after the meeting.
It's the latest in a series of contacts by the White House after Obama's announcement Saturday that he would seek congressional authorization before striking Syria.
"We will be stronger if we take action together, as one nation," Obama said.
In addition to the White House meeting, three key members of Obama's team are scheduled to testify before the Senate Foreign Relations Committee: Secretary of State John Kerry, Defense Secretary Chuck Hagel and Joint Chiefs Chairman Martin Dempsey.
Obama and Vice President Biden met with the lawmakers hours before the president was to depart for a trip to Europe.
After a stop in Stockholm, Obama will head to St. Petersburg, Russia, for a Group of 20 nations summit that is likely to be dominated by the Syria question. The G-20 figures to be part of Obama's effort to lobby world leaders in support of a strike at Syria.
The White House announced Tuesday that Obama spoke Monday night with Japanese Prime Minister Shinzo Abe about "their grave concern" regarding the use of chemical weapons in Syria.
"The two leaders agreed that the use of chemical weapons is a serious violation of international norms and cannot be tolerated," the White House said in a statement. "They pledged to continue to consult closely on possible responses by the international community."