MOSCOW (Reuters) -Kazakhstan's oil production has risen by 2% in May, an industry source said on Tuesday, an increase that defies pressure from OPEC+ on the Central Asian country to reduce its output.

Kazakhstan has repeatedly breached its OPEC+ production quotas, citing the difficulty of telling Western oil majors, such as Chevron and ExxonMobil, to curtail their plans.

The Organization of the Petroleum Exporting Countries and allies, a group known as OPEC+, has decided to speed up output increases, in part to punish members not complying with curbs by adding to downward pressures on international oil prices, OPEC+ sources have said.

Kazakhstan's oil production fell 3% in April, although it still exceeded its OPEC+ quota.

The country's energy ministry did not respond to a request to comment on production figures for May.

It said separately in emailed comments that production from the country's largest Tengiz field had reached its planned level, meaning the country's production would not increase further this year.

"Kazakhstan is taking all measures to comply with OPEC+ obligations and compensate for excess production," the emailed comments said further.

According to the industry source, who spoke on condition of anonymity due to the sensitivity of the situation, Kazakhstan's crude oil production, excluding gas condensate, averaged 1.86 million barrels per day on May 1-19, including 932,000 bpd at Tengiz.

This was up from 1.82 million bpd in April, when Kazakhstan reduced output from 1.88 million bpd in March.

Under the latest OPEC+ agreement, Kazakhstan's OPEC+ quota for May rose to 1.486 million bpd from 1.473 million bpd in April.

The country's energy ministry has repeatedly said it was committed to the OPEC+ agreement.

It has said it will compensate for overproduction by reducing its cumulative output by 1.3 million bpd by April 2026, while also saying it would prioritise national interests over those of OPEC+ when deciding on production levels.

Western oil majors, including Shell, TotalEnergies and Eni, as well as ExxonMobil and Chevron, are active in Kazakhstan oil projects.

"We expect Kazakhstan's production to stabilise at around 1.8 million bpd. Officials have highlighted limited flexibility in lowering output, given the field is controlled by international firms," Abu Dhabi Commercial Bank said in a note.