The United States and Canada will push for tougher measures – including naval interdiction – at next week's Vancouver summit to exert maximum pressure on North Korea to curb its nuclear and ballistic missile programs, a senior U.S. official said Thursday.

Foreign Minister Chrystia Freeland and U.S. Secretary of State Rex Tillerson will be hosts of the special summit on Jan. 16, which will include South Korea, Japan, India, Britain, France and other countries that fought in the Korean War of 1950-53.

Even though North Korea, China and Russia won't be at the table, a senior U.S. official said the Vancouver summit is not a "PR" exercise but an effort by Western countries to persuade North Korean leader Kim Jong-un to end his nuclear program.

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"There is growing evidence that our maximum pressure campaign is being felt in North Korea. They are feeling the strain," U.S. State Department policy director Brian Hook told a briefing in Washington on Thursday.

"We believe this pressure campaign remains the best avenue to force change in Kim Jong-un's behaviour and to get him to the negotiating table for meaningful discussions."

Among the issues the foreign ministers will be discussing is how the international community can thwart North Korea's efforts to evade United Nations sanctions through smuggling and financing of its nuclear and missile program.

Mr. Hook said the United States wants to see an increased focus on blocking ships from supplying North Korea with oil and components for its nuclear and missile development.

"Maritime interdiction helps us to disrupt resources and the financial side helps us to disrupt the financing of its nuclear and ballistic-missile program," he said.

There is no indication that Canada would deploy ships to the region to assist in this effort.

In December, South Korea seized two ships as part of what it describes as a continuing effort to monitor North Korea's attempts to evade UN sanctions. A Panamanian-flagged vessel and a Hong Kong-based ship were suspected of illegally selling oil to North Korea. The seizures came after the UN Security Council unanimously adopted new sanctions on North Korea in response to Pyongyang's Nov. 29 ballistic missile test.

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Mr. Hook said foreign ministers will also discuss asking the United Nations to list ships that have broken the UN sanctions ban.

"We think that would demonstrate seriousness of purpose if we can start having more of these vessels listed so that they can then be banned from entering other ports," Mr. Hook said.

Chinese Foreign Ministry spokesman Lu Kang said Wednesday the summit would not help because it didn't include key players and could harm joint efforts to improve the situation on the Korean peninsula. A Japanese Foreign Ministry official questioned the need for including countries as distant as Greece and Colombia.

But Mr. Hook said Washington has reached out to Beijing and Moscow and will provide them with readouts of the one-day meeting. The night before the summit, Ms. Freeland will be the host of a dinner for the delegates, which will be attended by Mr. Tillerson and U.S. Defence Secretary Jim Mattis.

The United States official also praised China, which shares a border with North Korea, for implementing UN sanctions.

Mr. Hook said a recent decision by Seoul and Pyongyang to reopen a cross-border hotline and to hold further talks during the Olympic Games in South Korea next month would not affect global efforts to keep the pressure on Mr. Kim to negotiate on the denuclearization of the Korean peninsula.

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He stressed, however, that Washington is not interested in regime change or collapse of the Democratic People's Republic of Korea. "Nevertheless we will not rest until the world is assured that the DPRK's pursuit of nuclear weapons has been verifiably abandoned," he said.

U.S. President Donald Trump suggested in an interview Thursday that he has developed a positive relationship with the North Korean leader, but declined to say whether they have spoken.

No sitting U.S. president is known to have spoken with a North Korean leader. The two countries have remained in a state of war and without diplomatic relations since the Korean War ended in 1953 without a peace treaty.

"I probably have a very good relationship with Kim Jong-un," Mr. Trump told The Wall Street Journal. "I have relationships with people. I think you people are surprised."

Asked whether he had spoken with Mr. Kim, Mr. Trump was evasive: "I'm not saying I have or haven't. I just don't want to comment."

Mr. Trump claimed credit Wednesday for the inter-Korean dialogue, saying North Korea was feeling the pressure of a U.S.-led campaign of sanctions. He said the United States was open to talks with North Korea under the right circumstances.

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International sanctions – such as cutting fuel imports and preventing North Korea from earning hard currency – are having an impact. More than 90 per cent of North Korea's publicly reported exports are now banned.

Recently, Malaysia kicked out North Korean labourers while Qatar and Kuwait halted work visas and the United Arab Emirates severed diplomatic relations. Peru, Spain and Italy have expelled North Korea's ambassadors.

The U.S. military is also sending an aircraft carrier and its battle group will be off the Korean coast during the Olympics.

With a report from Reuters