Revealed: The forgotten treaty which could drag the US and UK into WAR with Russia if Putin's troops intervene in Ukraine
The agreement sees signatories promise to protect Ukraine's borders
It was signed by Bill Clinton, John Major, Boris Yeltsin and Leonid Kuchma in 1994
Ukrainian parliament has now reached out directly to all the countries who signed the treaty
Putin currently has 150,000 troops on Ukraine's borders and it is reported some have crossed into the country
President Obama says he is 'deeply concerned' by the news
The US and Britain have both made 'crisis calls' to President Putin to warn him to respect territorial boundaries
By Jill Reilly and Lizzie Edmonds
PUBLISHED: 13:05 EST, 28 February 2014 | UPDATED: 21:47 EST, 28 February 2014
A treaty signed in 1994 by the US and Britain could pull both countries into a war to protect Ukraine if President Putin's troops cross into the country.
Bill Clinton, John Major, Boris Yeltsin and Leonid Kuchma – the then-rulers of the USA, UK, Russia and Ukraine - agreed to the The Budapest Memorandum as part of the denuclearization of former Soviet republics after the dissolution of the Soviet Union.
Technically it means that if Russia has invaded Ukraine then it would be difficult for the US and Britain to avoid going to war.
The revelation comes as reports suggest the Kremlin was moving up to 2,000 troops across the Black Sea from Novorossiysk to their fleet base at Sevastopol.
At least 20 men wearing the uniform of the Russian fleet and carrying automatic rifles surrounded a Ukrainian border guard post in a standoff near the port yesterday.