A White House spokesperson says the United States is carefully considering requests to eventually ship that country's excess supplies of COVID-19 vaccines across the border to its neighbours in Canada and Mexico.

But she cautions that nothing is confirmed at this point.

The comments come amid mounting anticipation of what might happen to the stockpile of doses in the U.S. after that country has enough supply for all its residents, likely by late May.

This week, U.S. President Joe Biden said he was speaking with several countries — without naming any. On Wednesday, Bloomberg News reported that Canada and Mexico topped Biden's list of priority export destinations, according to an administration official.

The issue was raised with White House spokesperson Jen Psaki, who replied with a warning that any shipments are not imminent. She said the U.S. still needs its vaccines, as 1,400 Americans are still dying of COVID-19 each day, and that the U.S. priority remains getting Americans vaccinated.

Psaki added, however, that the administration also wants to be a contributing member of the global community in getting the pandemic under control, and that there are requests from around the world.

"We have received requests from both Mexico and Canada and are considering those requests carefully," Psaki said.

"But I don't have any update for you on whether they will be granted, and a timeline for that."

Some members of the U.S. Congress have said it should be a U.S. priority to vaccinate others on this continent next, in order to get land borders reopened, citing the economic and human ties Americans have with those two neighbouring countries.