The decision, affecting hundreds of millions of dollars in U.S. military aid, has alarmed NATO allies and upset U.S. lawmakers who strongly back the alliance.

WASHINGTON, Sept 4 (Reuters) - U.S. President Donald Trump told European leaders on Thursday that Europe must stop buying Russian oil that he said is helping Moscow fund its war against Ukraine, a White House official said, striking a combative tone amid slow diplomatic progress to end the fighting.

NATO and the EU are working on ways to counter Russia's jamming of GPS systems aboard civilian flights. How does jamming work and what other "grey zone" techniques has Moscow been using in Europe? Vie

Amid last month's diplomatic efforts to pressure Russia into peace negotiations, new data showed that the European Union had imported Russian liquefied natural gas (LNG) worth around €4. 48 billion ($5.

European countries have pledged to surge defense spending, funneling investment into areas with large gaps, like air defenses.

The US is dramatically phasing out crucial security assistance programmes for European armies stationed along Russia's menacing border, as Donald Trump aggressively pushes the continent to cough up for more of its own defence.

Bulgarian authorities aren't investigating a suspected Russian interference operation involving a plane carrying European Commission President Ursula von der Leyen because they say the interference is now common.

Ending the longstanding program is expected to impact hundreds of millions of dollars that have gone toward countries that border Russia.

Sweden, NATO's newest member, moved to join the alliance along with neighboring Finland after Russia launched its full-scale invasion of Ukraine. Ukrainian officials have repeatedly said that Russia will attack further west in Europe if the Kremlin feels it has won in Ukraine.