With Greece's relations with its European counterparts at a low ebb, Greek Prime Minister Alexis Tsipras will head to Russia on Thursday and meet President Vladimir Putin at the St. Petersburg International Economic Forum (SPIEF).

Tsipras' visit comes at a , with reforms-for-rescue talks between the country and its international lenders in deadlock.

He is due to meet with Russian President Vladimir Putin on Friday afternoon, the Greek government said in a statement Thursday, and ahead of that meeting will make a keynote speech at the forum.

Tsipras' government has already warned it will not have the money to pay a debt of 1.5 billion euros to the International Monetary Fund (IMF) without an agreement, prompting increasing concern that Greece will default and eventually leave the euro zone.

However on Thursday, Russian Deputy Finance Minister, Sergei Storchak, said Greece had not asked the Russian Finance Ministry for financial assistance, Dow Jones reported. The ministry would not comment on the remarks when contacted by CNBC.

The head of the IMF, Christine Lagarde, said that Greece would be in default at the start of July if it fails to make a repayment on June 30 because there is no grace period or possibility to delay, Reuters reported.

"It will be in default, it will be in arrears vis-a-vis the IMF on July 1, but I hope it is not the case, I really do," Lagarde told reporters following a meeting with the Luxembourg finance minister.