The United States, Japan and South Korea are looking at new ways to restrict funding used for North Korea’s weapons programs, according to a joint statement after a meeting in the capital of the United States.

The parties held a trilateral meeting on the issue of Pyongyang’s weapons program funding on Monday in Washington, DC.

“The officials considered other possible measures under national authorities, including means to restrict further the revenue sources for North Korea’s weapons programs, particularly illicit activities,” the statement noted on Monday.

According to the statement, the officials from the three countries all view Pyongyang’s nuclear and ballistic missile program as a direct security threat.

The United States also reaffirmed its defense commitments to South Korea and Japan, including extended deterrence.

The representatives from the three nations also committed to leading the international response to any future violations of UN Security Council resolutions by North Korea, the statement added.

On Saturday, South Korean officials told local media that Seoul would take a hard line on North Korea for illegally storing biological and chemical weapons, at the talks with the United States and Japan, after a highly toxic liquid was confirmed to have killed the half-brother of the North Korean leader.

It was also reported by the South Korean media that the North Korean authorities could stand behind the murder of Kim Jong Nam.

Kim Jong Nam was killed on February 13 at the Kuala Lumpur International Airport while waiting for his flight. The highly toxic gas was sprayed in his face as he was about to board a flight to Macau.