Ukraine standoff: Joe Biden says Russia invasion has started as he reveals first sanctions

U.S. President Joe Biden announced on Tuesday new sanctions in retaliation for Russia recognising two breakaway regions of Ukraine and sending troops there, adding to Western efforts to stop what they fear is the beginning of a full-scale invasion.

The measures target Russian banks and sovereign debt, among other steps.

One of the worst security crises in Europe in decades is unfolding as Russian President Vladimir Putin authorised sending what he calls peacekeping troops to the separatist areas of Donetsk and Luhansk after recognising them as independent. Both adjoin Russia and have been controlled by Russian-backed fighters since 2014.

Weeks of intense diplomacy have so far failed as Moscow calls for security guarantees, including a promise that its neighbour Ukraine will never join NATO, while the United States and its allies offer Putin confidence-building and arms control steps.

"He's setting up a rationale to take more territory by force," Biden said at the White House.

"I'm going to begin to impose sanctions in response, far beyond the steps we and our allies and partners implemented in 2014," he added, in a reference to Russia's annexation of Crimea from Ukraine.

Sanctions are being applied to VEB bank and Russia's military bank, referring to Promsvyazbank, which does defence deals, Biden said. Starting on Wednesday U.S. sanctions will begin against Russian elites and their family members.

The hit to Russia's sovereign debt meant the Russian government would be cut off from Western financing, according to Biden.

Earlier on Tuesday, Germany put the brakes on a new gas pipeline from Russia and Britain also hit Russian banks with sanctions. The Russian foreign ministry criticised the new measures as "illegitimate".

The European Union also agreed new sanctions that will blacklist more politicians, lawmakers and officials, ban EU investors from trading in Russian state bonds, and target imports and exports with separatist entities.

Russian Foreign Minister Sergei Lavrov earlier brushed off the threat of sanctions.

"Our European, American, British colleagues will not stop and will not calm down until they have exhausted all their possibilities for the so-called punishment of Russia," he said.