US Vice President Kamala Harris will discuss the difficult issue of bringing Soviet fighter jets to Ukraine during her visit to Poland this week, senior administration officials said.

Harris' visit was complicated when Poland issued a surprise announcement saying it would donate its MiG-29 fighter jets to the United States rather than directly to Ukraine. This idea was categorically rejected by Washington.

There are a lot of ideas on the table. As you understand from the Pentagon statement, we believe that this claim is untenable, but we want and certainly encourage all allies to come up with ideas so that we remain in very close coordination across the board, a senior administration official said, CNN reports.

Harris will discuss the issue with Polish leaders, including the president and prime minister, when he meets with them Thursday in Warsaw, he said.

 In Warsaw, Harris will also meet with refugees, as well as US diplomats who have moved to Poland from the US embassy in Kyiv, which was closed.

She will also meet Canadian Prime Minister Justin Trudeau, who is visiting there, and speak with US and Polish military personnel on Friday.

The US deployed an additional nearly 5,000 troops to Poland.

From Poland, Harris will travel to Romania, where he will meet with the country's president and US embassy staff.