U.S. President Donald Trump and South Korea’s President Moon Jae-in have agreed to toughen sanctions against North Korea in a bid to curb the North's nuclear ambitions.

"The two leaders agreed to strengthen cooperation, and exert stronger and practical sanctions on North Korea so that it realizes provocative actions leads to further diplomatic isolation and economic pressure," Blue House spokesman Park Soo-hyun said in a televised briefing, Reuters reported.

The two leaders plan to work with the international community to implement U.N. Security Council resolution 2375, intended to put maximum economic and diplomatic pressure on North Korea following recent missile and nuclear tests.

North Korea's most recent test of an intermediate range ballistic missile flew 2,300 miles, making it capable of reaching the U.S. territory of Guam.

But despite pressure from the U.S. and its Asian allies, Kim doesn’t appeared to be backing down. North Korea state media quoted him as saying his country is going “full speed and straight” to the goal of “completing its nuclear force,” adding it is “nearly” there.

However, John DeLury of Seoul’s Yonsei University, a leading North Korea expert, believes Kim's tough talk might signal an “opening” to negotiations with the U.S. as he builds his nuclear arsenal -- talks that may be the only answer to the situation in Pyongyang.

“We've got to talk,” DeLury told Fox News. “What has to happen is a senior American official or a trusted confidant of President Trump needs to get in the room with a senior North Korean official or confidant of Kim Jong Un. Until the talks start, this process we’re watching is just going to go on and on and on.”

Perhaps Trump and Moon's most recent actions will finally bring Kim to the bargaining table.

Fox News' Greg Palkot contributed reporting to this story.