HOUSTON, July 22 (Reuters) - U.S. oilfield service provider Halliburton HAL.N on Tuesday said Mexico's crude production decline rates are creating pressure for a reactivation of business amid long delays from state-run Pemex to pay its suppliers.

Output of crude and condensate by Pemex, the largest producer in the country, fell 8.4% in May to 1.64 million barrels per day, according to official figures.

Oilfield service companies have significantly decreased activities because of the lack of payments from Pemex, the world's most indebted energy company.

Halliburton said issues related to payments from Pemex have not been resolved yet.

The Mexican association that groups foreign oil services companies warned last month that many of these firms may have to stop operations as early as July.

Halliburton, which posted second-quarter earnings on Tuesday, said it expects its full-year international revenue to decline by mid-single digits, year on year, primarily driven by activity reductions in Saudi Arabia and Mexico.

(Reporting by Arathy Somasekhar and Tanay Dhumal in Houston; Editing by Chizu Nomiyama )

((arathy.s@thomsonreuters.com; +1 832 610 7346; X: @ArathySom;))