Prior to World War II, “there were three million Jews in Poland. Three to four hundred thousand lived in Warsaw” . After five years of Nazi military occupation in Warsaw, opposition forces in the form of the Polish Resistance Army planned an organized uprising against occupying forces and had received promises for assistance from the Allied forces: Stalin’s Red Army, Great Britain, and the United States.
One of the friction points among the Allied Forces and Polish resistance forces could be found in the opposite forms of government represented between capital democracy and Soviet communism. While Germany was the main enemy to the USSR and the Capitalist-democratic forces of the West, resulting in all Allied parties involved making promises of support to the Polish opposition forces, a sub-level concern for the Polish opposition (and also a concern for the U.S. and Britain) was the possibility that the Soviets would institute a communist government over areas of Poland if they were able to force Germany out of Warsaw. After all, the democratic Polish government had, for the most part, taken exile in Britain and pro-democratic.
As the Red army approached Warsaw at the beginning of August of 1944, the Germans launched a fierce counter-attack with reinforcements, and several ground units within the Soviet military advance had their orders modified to move in a different direction or to halt advancement into Warsaw altogether. This reluctance in pursuing an all-out assault on German forces occupying Warsaw is debated by historians, with one of the main arguing theories being that the Warsaw insurgents supported an anti-Soviet exiled government and Stalin may have wanted that faction destroyed.
In the historical documentations below, we can see the coordinating efforts of the allied forces, similar to Western support for opposition uprisings in Syria and Egypt today, in attempting to arm the Warsaw Uprising.
Message dated August 4, 1944 from Winston Churchill to Stalin:
“At urgent request of Polish Underground Army we are dropping, subject to weather, about sixty tons of equipment and ammunition into the southwest quarter of Warsaw, where it is said a Polish revolt against the Germans is in fierce struggle. They also say that they appeal for Russian aid, which seems to be very near. They are being attacked by one and a half German divisions. This may be of help to your operation.” 
Message dated August 15, 1944 from Soviet Foreign Affairs Commissar to U.S. Ambassador to the USSR, William Harrison Standley in Moscow:
“The Soviet Government cannot of course object to English or American aircraft dropping arms in the region of Warsaw, since this is an American and British affair. But they decidedly object to American or British aircraft, after dropping arms in the region of Warsaw, landing on Soviet territory, since the Soviet Government do not wish to associate themselves either directly or indirectly with the adventure in Warsaw.” 
The correspondence to the U.S. Ambassador shows Stalin’s refusal to allow U.S. or British supply planes to land (and refuel) in Soviet territory.
Message dated August 16, 1944 from Stalin to Winston Churchill:
“After the conversation with M. Mikolajczyk I gave orders that the command of the Red Army should drop arms intensively in the Warsaw sector. A parachutist liaison officer was also dropped, who, according to the report of the command, did not reach his objective as he was killed by the Germans. Further, having familiarized myself more closely with the Warsaw affair, I am convinced that the Warsaw action represents a reckless and terrible adventure which is costing the population large sacrifices. This would not have been if the Soviet command had been informed before the beginning of the Warsaw action and if the Poles had maintained contact with it.” 
The message from Stalin basically shows his abandonment of support to the Warsaw uprising.
 Dale, Jon. The Warsaw Ghetto Uprising, 1943. Socialism Today, Issue 75, June 2003. Accessed from http://www.socialismtoday.org/75/warsaw43.html
 Churchill, Winston. Letter to Stalin Dated August 4, 1944, Public Domain. Accessed from http://www.warsawuprising.com/doc/Roosevelt_Churchill_Stalin.htm
 Vyshinsky, Andrey. Letter to Ambassador Harrison Dated August 15, 1944. Public Domain. Accessed from http://www.warsawuprising.com/doc/Roosevelt_Churchill_Stalin.htm
 Stalin, Josef. Letter to Winston Churchill Dated August 16, 1944. Public Domain. Accessed from http://www.warsawuprising.com/doc/Roosevelt_Churchill_Stalin.htm