President Joe Biden nominated Wednesday the son of Zbigniew Brzezinski, one of the most prominent figures in Cold War politics, as US ambassador to his ancestral Poland despite reported hesitation by Warsaw's right-wing government.

Mark Brzezinski, who will need Senate confirmation, is an investor who served in foreign policy roles in previous Democratic administrations including as ambassador to Sweden under Barack Obama.

The nomination had been rumored for weeks and a Polish news site, Onet.pl, reported that the government in Warsaw raised objections by arguing that Brzezinski holds Polish citizenship through his father, making him ineligible to be ambassador.

The Polish government denied the account which came as the Biden administration takes a firmer line on democratic values with nations including Poland, whose populist government was closely allied with former president Donald Trump.

The State Department has voiced alarm over attempts in Poland to amend a law that would force a US company to sell a stake in a television network, which would allow greater state control over the media.

Mark Brzezinski (left), tapped as US ambassador to Poland, greets then secretary of state Hillary Clinton when he was ambassador to Sweden in 2012
Mark Brzezinski (left), tapped as US ambassador to Poland, greets then secretary of state Hillary Clinton when he was ambassador to Sweden in 2012 AFP / SAUL LOEB

A group of US senators, mostly Democrats but also including the top Republican on the Senate Foreign Relations Committee, in a joint statement Wednesday voiced concern over the "troubling trajectory for Poland's democracy" and warned it would scare off US investment.

Mark Brzezinski speaks Polish and studied as a Fulbright Scholar in Poland after the fall of the Iron Curtain, researching the country's constitutional transition.

Zbigniew Brzezinski, who died in 2017, was the son of a Polish diplomat who became a naturalized American citizen and one of the leading tacticians during the Cold War.

As national security advisor to Jimmy Carter from 1977 to 1981, the elder Brzezinski pressed for a firm line against the Soviet Union, notably by backing Islamic guerrillas who fought back Moscow's invasion of Afghanistan.

Mark is the sister of prominent television journalist Mika Brzezinski, co-host of the MSNBC show "Morning Joe."