WASHINGTON (AP) — President Barack Obama says the world "has to step up" to help combat climate change and adds that the United Nations will continue to press other countries to take action.

Obama commented Tuesday following an Oval Office meeting with U.N. Secretary-General Ban Ki-moon.

A day earlier, Obama unveiled his plan to clamp down on power plant emissions.

Obama says he and Ban also talked about the crises in Syria, Yemen, Libya and South Sudan.

Obama reiterated his stance that both sides in South Sudan's civil war must meet an Aug. 17 deadline to end the bloodshed or face consequences.

In September, Obama is expected to attend the annual meeting of the U.N. General Assembly.