KIEV, Sept. 20 – President Viktor Yushchenko said Ukraine’s gas agreement with Russia can be changed at “any moment” and voiced support for state-run NAK Naftogaz Ukrainy’s plan to repay or swap $500 million of eurobonds.

Under the pact, Ukraine gets less for gas shipments than any other European country. That has generated a 33 billion-hryvnia ($3.9 billion) budget deficit for Naftogaz, which operates the pipeline network that ships gas to Europe, and forced it to seek outside financing, Yushchenko said.