Venezuela has reached a deal with its main financier China to improve the conditions of an oil-for-loans deal, giving the OPEC member's crisis-hit economy "oxygen" ahead of heavy debt payments, its top economic official said on Monday.

Venezuelan Economy Vice-President Miguel Perez told Reuters that all conditions, including loan time frames, investment amounts and non-financial aspects, had been improved.

Chinese Foreign Ministry spokesman Hong Lei told a regular press briefing on Tuesday that both sides "agreed to add more flexibility to strengthen financing cooperation," but he did not give details.

Perez said the improved China deal, as well as a steep cut to imports and a new, weaker foreign exchange rate, would help Venezuela crawl out of a "very complicated" semester.

The economy was likely to remain in recession until the end of 2017, he added.

China has lent some $50 billion to Venezuela in that arrangement over the last decade, and markets are watching to see if Beijing will help President Nicolas Maduro's socialist government as it struggles with recession, shortages and reduced oil revenue.

"Today we can say that we've agreed to new commercial conditions that are adapted to the country's reality," Perez said in an interview in his office at the Industry Ministry, which he also heads.

Better terms with China would be hugely useful for Venezuela, given that low oil prices mean the South American country would be required to send more barrels to meet its obligations.

"This will give the country important oxygen to go forward," added Perez, a former industry association leader who became economy czar in February, replacing a hard-line socialist.