Canadian Prime Minister Mark Carney arrived at the White House Tuesday for meetings with President Donald Trump.

The visit comes at a time when one of the world’s most durable and amicable alliances has been fractured by Trump’s trade war and annexation threats.

Carney’s second trip to the White House comes ahead of a review of the the U.S.-Mexico-Canada Agreement, which is critical to Canada’s economy.

Carney is looking to get some relief on some sector-specific tariffs, but expectations are low.

More than three-quarters of Canada’s exports go to the U.S. Trump’s talk of making Canada the 51st state and his tariffs have Canadians feeling an undeniable sense of betrayal. Relations with Canada’s southern neighbor and longtime ally are at a low point.

The ties between the two countries are without parallel. About $2.5 billion (nearly $3.6 billion Canadian) worth of goods and services cross the border each day.

Canada is the top export destination for 36 U.S. states. There is close cooperation on defense, border security and law enforcement, and a vast overlap in culture, traditions and pastimes.

About 60% of U.S. crude oil imports are from Canada, and 85% of U.S. electricity imports are from Canada.

Canada is also the largest foreign supplier of steel, aluminum and uranium to the U.S. and has 34 critical minerals and metals that the Pentagon is eager for and investing in for national security.

AP Video shot by Dan Huff