HIROSHIMA, Japan, May 21 (Reuters) - U.S. President Joe Biden announced a new $375 million package of military aid to Ukraine on Sunday and told President Volodymyr Zelenskiy that the United States was doing all it could to strengthen Ukraine's defense for the war with Russia.

Meeting with the Ukrainian leader on the sidelines of the G7 summit of world leaders in Hiroshima, Japan, Biden said the military aid package included ammunition, artillery, armored vehicles and training.

"Together with the entire G7, we have Ukraine's back and I promise we're not going anywhere," Biden told Zelenskiy.

In the meeting, Biden stressed his country's readiness to help build Ukraine's long-term capacity to defend against and deter Russian aggression, the White House said.

To that end, Biden discussed U.S. support for a joint effort with allied and partner nations to train Ukrainian pilots on fourth-generation fighter aircraft such as the F-16, it said.

Zelenskiy thanked the United States for the new package, and for the financial assistance of $37 billion to date, his office said.