SEOUL—North Korea’s launch of a long-range rocket triggered condemnation and prompted Washington and Seoul to formalize talks over deploying an advanced missile shield to South Korea, a move China strongly opposes.

The United Nations Security Council, after an urgent meeting Sunday, said the rocket launch was a threat to world security and a clear violation of U.N. resolutions banning North Korea from developing its nuclear program.

The Security Council said its members were consulting on a resolution that would impose tougher and more robustsanctions on North Korea, in hopes of altering its behavior. “The members of the Security Council restated their intent to develop significant measures in a new Security Council resolution,” said the statement.

Defying a U.N. ban on testing ballistic-missile technology, North Korea said it put a satellite into space from a multistage rocket launched about 9 a.m. local time Sunday. South Korea said an object had been put into orbit by the rocket, but it wasn’t clear if it was transmitting back to earth.

A statement from North Korea’s state news agency said the nation would launch more satellites, and attributed the latest achievement to leader Kim Jong Un.