MOSCOW—Belarus said on Monday it is close to securing a $400 million loan from Iran as the authoritarian Eastern European nation scrambles to line up financing from its few allies amid a deepening economic crisis.

Meanwhile, the International Monetary Fund will visit the country starting Tuesday after rebuffing requests for a loan last month, although few observers expect an IMF deal anytime soon.

Iran may lend the country $400 million, while Russia's biggest state-controlled bank may lend up $1 billion backed by shares in the Naftan oil refinery, officials from President Alexander Lukashenko's government said on Monday, according to the official state news agency.

Since his controversial re-election last year, Mr. Lukashenko has increasingly become isolated from the U.S., which recently toughened sanctions, as well as from Europe and even Russia.

The Belarusian ruble has lost three-fifths of its value against the dollar in the past year, and foreign reserves have fallen to a level that puts the economy at risk, according to officials and analysts.