U.S. Senator John McCain says the U.S. should board a North Korean ship even without Pyongyang’s permission if hard evidence shows it is carrying missiles or other cargo in violation of U.N. resolutions.

Appearing on CBS’s “Face the Nation,” McCain said Sunday that cargo which violates U.N. resolutions can contribute to the proliferation of weapons of mass destruction to rogue nations that pose a direct threat to the United States.

McCain called the recent U.N. Security Council’s adoption of sanctions against the North “an inadequate half-measure,” stressing that the most important part of dealing with the Pyongyang situation is to get China more involved.

McCain, who lost to President Barack Obama in the 2008 presidential race, said he thinks the president has done well in his first five months in office.