According to the analyst, the ruble began June with a strengthening against the dollar and the euro, despite the fall in oil prices and the end of the May tax period.

"The main factor influencing the ruble is, most likely, the retreat of the threat of default of the United States on the national debt and, accordingly, the resumption of market interest in riskier currencies of developing countries," Milchakova said.

She added that the results of the OPEC+ ministerial meeting, which will be held in Vienna on June 4, will begin to affect the foreign exchange market.

"Most likely, for the oil and foreign exchange market, it will be important not so much the decision of OPEC+ on production quotas, which, apparently, will not be changed, as the statements and forecasts of the ministers of OPEC+ countries, primarily Saudi Arabia and Russia," the interlocutor of RT explained.

Another important factor of influence Milchakova called the decision of the Bank of Russia on the key rate.

"Next week we can expect the dollar exchange rate of 79-82 rubles, the euro - 85-88 rubles," she said.

Earlier, economist Scott McDonald said that a potential default in the United States could lead to serious consequences for the US dollar and the country's economy.