exican President Andres Manuel Lopez Obrador is expected to ask President Joe Biden to consider sharing part of the US coronavirus vaccine supply with its southern neighbor when the two leaders hold a virtual summit on Monday, US and Mexican officials said, Reuters reported.

Biden is open to discussing the matter as part of a broader regional effort to cooperate in the fight against the COVID-19 pandemic but will maintain as his “number one priority” the need to first vaccinate as many Americans as possible, a White House official said on condition of anonymity.

Lopez Obrador has been one of the most vocal leaders in the developing world pressing the richest countries to improve poorer nations’ access to the vaccines. He has called the current distribution system “totally unfair.”

While Biden has increased funding for international efforts to combat COVID-19, he could face political fallout if he moves too fast to ship vaccines to other countries when the United States is ramping up but still struggling to meet domestic needs.

Mexico’s inoculation program has been delayed by slow shipments, despite agreements with international drugmakers meant to purchase doses for the country’s 126 million people.

With Pfizer Inc deliveries running behind schedule, Mexico has scrambled to fill the gap, landing initial deliveries of Russia’s Sputnik V and China’s Sinovac.

Mexico has had more than 185,000 COVID-19 deaths and more than 2 million coronavirus infections.