Dmitry Rogozin, Russia’s deputy prime minister, has said all American GPS sites are to be banned inside Russian borders temporarily, starting in June.

“Starting June 1, we will halt the work of those stations on Russian territory,” Rogozin said. Rogozin, who is in charge of the Space and Defense ministries, referred to dated agreements made several years ago in 1993 and 2001.

“Under this agreement there are 11 GPS stations on the territories of 10 [Russian federal] subjects,” he said.

The state of the ban will depend on negotiations between Moscow and Washington ending on May 31. The negotiations concern a decision of whether to place Russian GLONASS stations on American soil or not.

GLONASS is one of the main rivals of GPS and its inception started in the Soviet Union. After falling under neglect, Russia’s aerospace program later revitalized the project. GLONASS is projected to potentially have more accuracy than GPS. However, GPS, being the more mature system of the two, is compatible with many more consumer products.

Rogozin warned that GPS operations in Russia would ‘be permanently terminated’ if talks between the two countries do not prove successful.

Compatibility between other global positioning systems, like Galileo being worked on by the EU, GLONASS, and GPS, may grind to a halt if the talks are not successful. Even more is on the line as well, since Rogozin went on to say that Moscow would also cease the United States use of Russian-made rocket engines to deliver satellites into space. Some of the satellites belonged to the military.

“We proceed from the fact that without guarantees that our engines are used for non-military spacecraft launches only, we won’t be able to supply them to the US,” Interfax news agency quoted Rogozin as saying.

The cessation of their use would arise from Russia not participating in maintaining the engines, something which the country’s engineers have already done so far. Russian’s Deputy Prime Minister warns that U.S. global positioning system stations in Russia’s borders could be done away with if an agreement is not reached between Washington and Moscow by May 31.