The purpose is to allow Kyiv to step up its attacks on targets in Russia and thus put increased pressure on the Kremlin, the newspaper writes, citing anonymous American government representatives.
It is mainly about British-made Storm Shadow missiles that are fired from Ukrainian fighter jets with a range of nearly 30 miles. The US can limit Ukraine's use of the missiles because they use American tracking information, WSJ writes.
Ukrainian military has stated that they used the weapon on Tuesday evening in an attack on a Russian factory that manufactures military equipment.
Decision mandate moved
US former President Joe Biden approved Ukraine's use of Storm Shadow, as well as American so-called Atacms missiles, against targets in Russia during the end of his term. But after Donald Trump took office, the Pentagon introduced a procedure that meant the US Secretary of Defense had to approve Ukrainian use of the weapons in cross-border attacks, WSJ writes.
Recently, however, the decision mandate was moved to the US's top general in Europe, also NATO commander, Alexus Grynkewich – and it is after that Ukraine got the green light to use the weapons, according to the newspaper's sources.
Dismissed by Trump
The White House has not officially announced this.
Trump dismisses that the US has approved the use of long-range missiles "deep into Russia".
"The US has nothing to do with those missiles, wherever they come from or what Ukraine does with them!", the president writes on Truth Social.
Storm Shadow should not be confused with the much more capable Tomahawk missiles, with a range of around 160 miles, which Ukraine is eagerly seeking. Trump has previously shown some openness to providing Ukraine with such missiles, but has recently backed down on the issue.