Military clashes between pro-Russian rebels (backed by Russian military) and the Ukrainian Armed Forces began in the east of Ukraine in April 2014. On 5 September 2014, the Ukrainian government and representatives of the self-proclaimed Donetsk People's Republic and the Luhansk People's Republic signed a tentative truce (ceasefire – the agreement). The ceasefire imploded amidst intense new fighting in January 2015. A new ceasefire agreement has operated since mid-February 2015, but this agreement also failed to stop the fighting. In January 2018, the Verkhovna Rada passed a law defining areas seized by the Donetsk People's Republic and the Luhansk People's Republic as "temporarily occupied by Russia", the law also called Russia an "aggressor" state. Russia has been accused by NATO and Ukraine of engaging in direct military operations to support the Donetsk People's Republic and the Luhansk People's Republic. Russia denies this, but in December 2015, Russian Federation President Vladimir Putin admitted that Russian military intelligence officers were operating in Ukraine, insisting though that they were not the same as regular troops. Russia has admitted that Russian "volunteers" are helping the separatists People's Republics.