Washington - The White House says it is treating the baby formula shortage as a top priority and there is growing concern that Canada could be affected by the U.S. response.

Over the weekend, military transports moved more than 35,000 kilograms of baby formula to the United States from Europe and more shipments are on the way.

President Joe Biden has relied on the Defense Production Act, a military procurement law from the 1950s, to ensure American manufacturers get the raw materials they need to ramp up production.

The shortage was caused by the closure of a major factory in Michigan in February, but international trade experts say the real problem is that the American industry is dominated by only a few main players.

Brian Deese, director of the White House National Economic Council, says too few American companies exercise significant control over the supply chain.

Deese told CNN on Monday: "Right now, our focus is on getting formula to families in need."

Prime Minister Justin Trudeau said Ottawa is closely monitoring the situation for fear U.S. efforts could ultimately increase the shortage in Canada.

Trudeau said last week: "We need to make sure we’re looking for solutions here in Canada."

The largest factory in Canada is the China-owned Canada Royal Milk plant in Kingston, Ontario, but 100 percent of its production is exported for domestic sale in China.

Editing: Dima Abu Khair