The demonstrations were mainly against the high cost of diesel, expensive insurance rates, European Union measures to protect the environment and pressures on the domestic market from imported Ukrainian agricultural goods.
Convoys of tractors and trucks began gathering six days ago on national roads, mainly near large cities in the EU and NATO state, slowing or blocking traffic.
The protesters' demands include a moratorium on loan repayments, faster subsidy payments and separate lines at border crossings and the Black Sea port of Constanta for EU lorries and trucks from outside the bloc, including Ukraine.
On Monday, trucks and tractors took position on roads leading to the checkpoints of Siret and Vicovu de Sus on the border with Ukraine, slowing transit, but Romanian border police said customs formalities were still being completed.
The Constanta port authority told Reuters that protests had not disrupted operations. The largest gathering of protesting hauliers was on the outskirts of the capital Bucharest.
Ukraine is one of the world's biggest grain exporters and Constanta has become Kyiv's largest alternative export route since Russia's full-scale invasion in February 2022, with grains arriving at the port by road, rail and barge across the Danube.
Hungary's agriculture ministry said on Monday eastern EU states Bulgaria, Poland, Hungary, Romania and Slovakia had sent a letter to the European Commission requesting the EU impose import duties on Ukraine grains, citing unfair competition.
Such duties were lifted for Ukraine after Russia's invasion blockaded its own ports to enable the transit of grains to global markets.
(Reporting by Luiza Ilie; editing by Mark Heinrich)
