Poland will simplify veterinary controls and add inspectors in an effort to boost the volume of Ukrainian grain exports through its territory, Ukraine's agriculture ministry said, after a pact signed by the neighbours.

With Ukraine's ports blocked off by Russia's invasion, the major grain grower and global exporter is forced to send shipments across its western border, relying on limited railroad capacity and small Danube river ports.

Traders and officials have said customs procedures and sparse Polish officials limit capacity at Ukrainian-Polish border crossings, however.

"The measures envisaged ... will significantly simplify the border crossing of our grain goods and increase export volumes, which is the ministry's priority," Ukraine's agriculture minister, Mykola Solskiy, said in a statement on Monday.

Ukraine's grain exports have more than halved in the first 10 days of May to about 300,000 tonnes, from 667,000 tonnes in the corresponding period last year.

It exported up to 6 million tonnes of grain each month before Russia's invasion in February, which Moscow has described as a "special military operation".

Last week, ministry data showed Ukraine has exported 46.17 million tonnes so far in the season from July 2021 to June 2022, against 39.65 million a season earlier.

In April, 3.5 million tonnes of cargo was carried by rail across the western borders, Ukraine's infrastructure ministry said this month.

Railway operators are setting up border terminals to handle general and liquid cargoes, as well as for reloading from wide gauge track to narrow gauge, and vice versa.

(Reporting by Pavel Polityuk; Editing by Clarence Fernandez)