U.S. Department of Justice does not satisfy with German pharmaceutical giant Bayer AG’s proposal to win approval to buy American seed and weed-killer company Monsanto Co. Bayer had pledged to sell certain seed and herbicide assets for $7.26 billion.

Bayer AG’s plan to win antitrust approval to buy U.S. seeds supplier Monsanto Co has not satisfied U.S. officials, who are worried the $62.5 billion merger could hurt competition, Bloomberg reported. The U.S. Department of Justice wants Bayer to divest more assets to satisfy its conditions, and does not think the German chemicals company’s current proposal is sufficient, cites people familiar with the matter. A Bayer spokesman said the company would not comment on rumors, but added it remains in talks with regulators to help close the deal in the second quarter of the year. Bayer had pledged to sell certain seed and herbicide assets for 5.9 billion euros ($7.26 billion) to German chemical company BASF to address EU regulatory concerns and has separately offered to sell its vegetable seeds business to BASF. The company has secured an approval from Brazilian regulators for the merger, while it is in the frame to win conditional antitrust approval from the European Union, Reuters reported. Bayer also has conditional approval from China’s commerce ministry.