https://en.wikipedia.org/wiki/President_of_the_United_States

Eligibility

Article II, Section 1, Clause 5 of the Constitution sets three qualifications for holding the presidency. To serve as president, one must:

• be a natural-born citizen of the United States;
• be at least 35 years old;
• be a resident in the United States for at least 14 years.[126]

A person who meets the above qualifications would still be disqualified from holding the office of president under any of the following conditions:

• Under Article I, Section 3, Clause 7, having been impeached, convicted and disqualified from holding further public office, although there is some legal debate as to whether the disqualification clause also includes the presidential office: the only previous persons disqualified under this clause were three federal judges.[127][128]
• Under Section 3 of the Fourteenth Amendment, no person who swore an oath to support the Constitution, and later rebelled against the United States, is eligible to hold any office. However, this disqualification can be lifted by a two-thirds vote of each house of Congress.[129] There is, again, some debate as to whether the clause as written allows disqualification from the presidential position, or whether it would first require litigation outside of Congress, although there is precedent for use of this amendment outside of the original intended purpose of excluding Confederates from public office after the Civil War.[130]
• Under the Twenty-second Amendment, no person can be elected president more than twice. The amendment also specifies that if any eligible person serves as president or acting president for more than two years of a term for which some other eligible person was elected president, the former can only be elected president once.[131][132]

So, going down the list:

• Pope Leo XIV was apparently born in Chicago, so he meets the natural-born citizen requirement.

• Pope Leo XIV was born in 1955, so he’s 70 and meets the 35 years of age requirement.

• It looks like, checking other sources, that the 14 year resident is just a requirement for cumulative residency over one’s life. Unless he has other things he did that Wikipedia doesn’t mention, he was in the US until he joined a mission to Peru in 1981, so he should meet the residency requirement.

• He has not been impeached and convicted, so he meets that requirement.

• He has not rebelled against the US, so he meets that requirement…

• He has not yet been elected to be President more than twice, so he meets that requirement.

According to WP, he’s still a US citizen.

So I expect that he could. There are no restrictions on also being a foreign citizen (he is a citizen of Peru and Vatican City as well) or of not also being concurrently a foreign head of government.