President Trump spoke with the leaders of South Korea and Japan on Friday as the region prepares for the start of the Winter Olympics in Pyeongchang, South Korea next week, the White House said.

Both conversations focused primarily on North Korean aggression. The Trump administration has stepped up its warnings to North Korea in recent weeks ahead of the games in South Korea, which will bring thousands of spectators and athletes from around the world into the backyard of Kim Jong Un's increasingly provocative regime.

"President Donald J. Trump spoke today with President Moon Jae-in of the Republic of Korea to wish him and the Korean people a successful Winter Olympic Games," the White House said in a readout of Trump's call to the South Korean president on Friday.

"The two leaders discussed the importance of improving the human rights situation in North Korea and underscored their commitment to work together on this issue," the White House said. "President Trump also reiterated his commitment to addressing the trade imbalance between the two countries."

Trump's phone call Friday with Japanese Prime Minister Shinzo Abe also centered on North Korea and the "maximum pressure campaign" the administration has called on the international community to help implement.

"President Trump thanked Prime Minister Abe for Japan’s efforts to maintain international pressure on North Korea, including recent efforts to clamp down on North Korea’s attempts to circumvent sanctions in the waters surrounding the Korean Peninsula," the White House said. "Both leaders agreed on the need to intensify the international maximum pressure campaign to denuclearize North Korea. The two leaders discussed the pending relocation of a United States Marine base on Okinawa and discussed ways to strengthen Japan’s defense capabilities including an expanded missile defense system."

Vice President Mike Pence will lead the U.S. delegation to the Winter Olympics, which begin on Feb. 9.