KIEV, June 3 - Prime Minister Volodymyr Hroysman said on Friday he would not let his decision-making be shackled by powerful vested interests, allowing him to push through reforms and usher in a period of economic stability.

In his first interview with foreign media since taking office in April, Hroysman told Reuters he was confident of receiving a further installment of aid worth $1.7 billion from the International Monetary Fund, which is contingent on implementing reforms.

He will travel to Washington in mid-June, with Ukraine having recently taken two major steps - freeing up gas prices and passing legislation to tackle corruption in the judiciary - under its commitments in a $40 billion international bailout deal.

The appointment of Hroysman, 38, ended months of political turmoil that had stymied policymaking. He had cut his teeth as Ukraine's youngest-ever mayor, at 28, before becoming speaker of the rough-and-tumble parliament.

Since the fall of communism, Ukraine's business oligarchs have frustrated efforts by a succession of governments to reform the economy, most recently in the form of changes promised by pro-Western leaders after street protests toppled the previous president in 2014.

Asked if he could free himself from the oligarchs' influence, Hroysman said: "I consider myself to be completely free in terms of my views and my decision-making."

"I can be dependent only on Ukrainian society," he added. "We will fight for every reform, for every change, fight transparently."

Hroysman took power with Ukraine just emerging from recession, still fighting a war against Russian-backed separatists in the eastern Donbas region and amid growing disillusion with the pace of change since the 2014 uprising.

A ceasefire agreement negotiated by Ukraine, Russia and Western powers is barely holding, with each side accusing the other of failing to honor their promises.

The IMF and Ukraine's other main backers - the European Union and United States - have also urged Kiev to speed up the reforms and tackling of endemic corruption.

An agreement for more IMF aid had been derailed by the political turmoil in Kiev. An IMF mission visited in May for talks on a new memorandum, which is still being drafted, and the Fund is expected to decide on disbursing new aid in July.

"During the last IMF mission, we had a constructive and frank discussion about the problems, and we found a common ground that allows us to move on," Hroysman said.

"I do not see anything that would prevent us to get (the next installment)," he added. "I am optimistic about our continued co-operation with the IMF."

"We need to ensure macroeconomic stability," he said. "This requires fighting corruption with deregulation, privatization, and an effective judicial system," he said. (rt/ez)