U.S. President Barack Obama on Tuesday welcomed Indonesia's ratification of the Comprehensive Test Ban Treaty (CTBT). In a statement released by the White House Press Office, Obama said that the U.S. welcomes the ratification, which “provides a strong example of the positive leadership role Indonesia can play in the global effort to prevent the spread of nuclear weapons.” “The Comprehensive Test Ban Treaty is a critical element of the international effort to prevent the proliferation of nuclear weapons and I urge all states to sign and ratify the agreement so that it can be brought into force at the earliest possible date,” Obama said in the statement. “The United States remains fully committed to pursuing ratification of the Test Ban Treaty and will continue to engage members of the Senate on the importance of this Treaty to U.S. security. America must lead the global effort to prevent proliferation, and adoption and early entry into force of the CTBT is a vital part of that effort.”