Japan’s ambassador to Canada says North Korea’s nuclear test on Friday was a “clear violation” of United Nations Security Council resolutions and that Japan has to be prepared for military action if necessary.

The latest detonation -- the country’s second in eight months -- has heightened concerns that North Korea is building lighter, smaller nuclear weapons capable of being mounted on missiles and striking as far away as North America’s west coast.

Speaking to CTV’s Power Play on Friday, Kenjiro Monji said Japan supports a peaceful resolution but has taken steps to defend itself, including the use of missile defence capabilities.

“We already have a current missile defence system with the United States and on our own, so I think that … plays a very important role,” Monji said. “We should be ready to defend ourselves.”

The Sea of Japan divides North Korea from Japan by several hundred kilometres, and Monji said it is believed that North Korea has the technology capable of striking Japan.

“They are certainly upgrading those technologies,” he said.

Since the test, which triggered a 5.0-magnitude quake, Japan has launched a “strong protest” against North Korea and condemned the test in “the strongest possible terms,” Monji said.

“This poses great concern to the security of Japan and undermines the peace and stability of the region and the international community,” Monji said.

He said Japan’s national security council has held a meeting since the test. The UN Security Council also met Friday afternoon for an emergency meeting.

“I hope there will be some concrete discussions,” Monji said of the UN meeting.

Leaders from across the globe stepped forward Friday to criticize North Korea’s actions. South Korean President Park Geun-hye said Kim Jong Un "is spiraling out of control" and called the test "fanatic recklessness." U.S. President Barack Obama said the U.S. will never “accept North Korea as a nuclear state.”

Prime Minister Justin Trudeau said the nuclear test is an "unacceptable violation" of UN Security Council resolutions. In a statement on Friday, Foreign Affairs Minister Stephane Dion said Canada “condemns in the strongest terms” the test.

"We call upon North Korea to comply with its international obligations, take concrete steps toward denuclearization and re-engage in meaningful negotiations for a peaceful political solution," the statement read.

Monji said Japan “fully appreciates” Canada’s support.

With files from the Associated Press