Former prime minister Stephen Harper is poised to meet with two top Trump administration officials in Washington against a backdrop of fractious talk over tariffs, CBC News has confirmed.

Harper is expected to travel to Washington on Monday, July 2, and has scheduled meetings with Larry Kudlow — the director of the National Economic Council and Trump's go-to economic adviser — and John Bolton, the president's national security adviser, according to multiple sources who spoke to CBC News on the condition of anonymity.

Kudlow, who recently suffered a heart attack but is now back on the job, was one of the president's surrogates who went on TV after the G7 summit in Charlevoix to attack Prime Minister Justin Trudeau personally over his plan to impose retaliatory tariffs on the U.S. Kudlow is one of Trump's most trusted economic advisers.

Senior White House economic adviser Larry Kudlow calls on a reporter during a briefing about the G7 summit, at the White House in Washington on Wednesday, June 6, 2018. (Susan Walsh/Associated Press)

CTV News first reported Harper's planned meeting with Bolton in Washington, citing details contained in emails the broadcaster had obtained.

Sources told CBC News that Harper, who now works as a consultant after leaving federal politics, personally approached the two officials to ask for a meeting.

Harper has not shied away from wading into the NAFTA talks, offering commentary on TV and at conferences. He has criticized some of the Liberal government's actions on the trade file while defending the NAFTA agreement itself.

Sources say that ahead of the meeting, Bolton phoned the Canadian embassy in Washington to make some arrangements — a call that caught Canadian officials off-guard as they were not expecting such a visit.

Adding to the confusion, say the sources, the White House did not specify which "prime minister" was expected for the meetings; the Americans often use political titles long after a politician has left office. That led some Canadian officials to believe a visit by Prime Minister Justin Trudeau had been planned in secret.

Trudeau's foreign policy adviser, John Hannaford, contacted his counterpart in the White House, who apologized and explained it was former prime minister Harper who would be visiting.

That prompted confusion on the part of Trudeau's inner circle, the sources say, as it's customary for past prime ministers to keep their successor in the loop on foreign travel plans of this magnitude.

This was also an issue when Harper himself was in office and he had to contend with former prime minister Jean Chrétien travelling to Russia to meet with President Vladimir Putin during the Crimean crisis. Harper had taken a tough stand against Putin and his incursion into Ukrainian territory.

In addition to his consulting work, Harper meets often with international conservative leaders as chair of the International Democrat Union, an alliance of conservative and centre-right parties founded 35 years ago by Britain's Margaret Thatcher, Germany's Helmut Kohl and then-U.S. vice president George Bush Sr., among others.

Thank you to President Pastrana for his invitation to join @CDI_IDC meetings in Brussels today. I appreciate all the interest in the <a href="https://twitter.com/hashtag/IDU?src=hash&ref_src=twsrc%5Etfw">#IDU</a> this week, and as IDU Chairman I look forward to continuing to engage with conservatives globally wherever I travel. <a href="https://t.co/GyItsomD88">pic.twitter.com/GyItsomD88</a> —@stephenharper

Canada readies final tariff list

Relations between Canada and the U.S. have soured considerably in recent weeks after Trump slapped punitive tariffs on Canadian aluminum and steel imports as part of his drive to protect the U.S. industry from what he claims is unfair foreign competition. His administration has sought to justify the tariffs on national security grounds.

A 25-per-cent tariff will be levied on Canadian steel, while a 10 per cent tariff will be applied to aluminum. In response, Canada has vowed to impose $16.5 billion worth of new tariffs on a host of U.S. goods, from lawnmowers to playing cards and felt-tipped pens.

The final list of U.S. goods to be taxed will be released tomorrow by Foreign Affairs Minister Chrystia Freeland and will take effect as of July 1.