Romania has been asked to pay "immediately" the $5.8 million it owes the U.S. government for agricultural commodities and to provide a "full explanation" of why it has gone into arrears on federal loans.

"We're asking them to bring their payments up to date immediately," State Department spokesman Dean Fischer said yesterday.

The Romanians' failure to pay has been known at the Commodity Credit Corp., the Department of Agriculture's bank, since Jan. 30, when the New York-based First Chicago International Bank advised the CCC that it had been unable to collect $319,108 due on a commodity loan.

On Tuesday, European-American Bank in New York informed the CCC that Romania had reneged on $5,465,259 due on a similar loan.

Fischer said not until Wednesday did the State Department learn of the arrearages.

Romania has yet to formally request that the government reschedule the $91.3 million in loans or loan guarantees coming due this year for farm sales.

In a new development, the Romanian Bank for Foreign Trade this week for the first time advised 19 U.S. banks that it was experiencing payments problems and that it had discussed the situation with representatives of the International Monetary Fund and some major western creditors.

Nonpayment of CCC loans automatically forces the U.S. government to choose between declaring Romania in default --which could trigger an international scramble by banks and companies to seize Romanian assets--or allowing delays in repayment, as has been done with Poland.