Obama Pledges Full US Support to Probe Bombings in Brussels

President Barack Obama said the U.S. would do "whatever is necessary" to support Belgium in bringing those responsible for Tuesday's deadly terrorist attacks across Brussels to justice, and called on the world to unite against terrorism.

"We must be together regardless of nationality or race or faith in fighting against the scourge of terrorism," Obama said at the beginning of a speech to the Cuban people in Havana. "The thoughts and the prayers of the American people are with the people in Belgium and we stand in solidarity with them."

Explosions ripped through the Brussels airport and a subway station on Tuesday, leaving at least 31 dead and more than 180 injured. Authorities there were on high alert and the U.S. embassy advised Americans in the country to shelter in place.

Obama was briefed earlier Tuesday on the attack by U.S. national security officials, and spoke with Belgian Prime Minister Charles Michel by phone to offer his condolences. Obama offered assistance in investigating the attacks and bringing those responsible to justice, and pledged the full cooperation and support of the U.S. in the fight against terrorism, the White House said.

Paris Attack

The attacks came four days after Belgian police captured Salah Abdeslam, who had been the subject of an intense manhunt over his alleged role in the November massacre in Paris. The four-month search prompted tough questions over whether Belgium had the necessary counter-terrorism resources to combat a growing jihadist threat in some of its poorest neighborhoods, and whether the government was doing enough to stem the flow of its citizens to the Middle East to fight with terror organizations, including the Islamic State.

The attack also comes as the U.S. and other world powers work to maintain a fragile ceasefire agreement in Syria. The administration hopes the deal could be a precursor to a political settlement that will calm that nation's ongoing civil war and allow an intensified campaign against Islamic State.

Congressional leaders said they expected to be briefed by the Obama administration on the attacks later in the day. 

'Closely Monitoring'

Marsha Catron, a spokeswoman for the U.S. Department of Homeland Security, said the agency was "closely monitoring the unfolding events" and in touch with its European counterparts.

"DHS will not hesitate to adjust our security posture, as appropriate, to protect the American people," she said in a statement.

Democratic presidential candidate Hillary Clinton said the attacks would "only strengthen our resolve to stand together as allies and defeat terrorism and radical jihadism around the world." Republican front-runner Donald Trump said in an interview with NBC's Today Show that the U.S. should "close up our borders until we figure out what's going on" and called for the use of waterboarding and other enhanced interrogation techniques on terrorism suspects.

The New York City Police Department said it had deployed additional counter-terrorism resources to crowded areas and transit locations across the city, and was working with federal authorities to monitor the situation. The transit system in Washington, D.C., said it was increasing canine sweeps and patrols Tuesday as a precaution. Both agencies said they were not aware of any direct threat to their cities.

With assistance from Angela Greiling Keane.