President Donald Trump and his top envoy to the U.N. say the latest sanctions against North Korea are necessary to try to curb the reclusive nation’s nuclear program.

Trump early Tuesday tweeted: “After many years of failure, countries are coming together to finally address the dangers posed by North Korea. We must be tough & decisive!”

U.N. ambassador Nikki Haley told NBC’s “Today” show that she isn’t sure whether the sanctions will work. North Korea’s leader, Kim Jong Un, has expressed no interest in walking away from his nuclear and ballistic missile program, and the country has survived past sanctions.

But Haley says the sanctions force Kim to rethink his “endgame.” She said: “He has to decide. If he strikes the United States, is that something he can win?”

(AP)