The United States and China may be in the final weeks of discussions to hammer out a deal to ease their tit-for-tat tariffs dispute, U.S. Trade Representative Robert Lighthizer said on Tuesday, Reutres reported.

“Our hope is we are in the final weeks of having an agreement,” Lighthizer, the top U.S. trade official, said during a U.S. Senate Finance Committee hearing on Tuesday, though he cautioned that major issues remained.

“If those issues are not resolved in favor of the United States, we won’t have a deal.”

Lawmakers pressed Lighthizer for details on whether the Trump administration intends to keep its tariffs in place to ensure China is complying with any agreement. President Donald Trump has vowed to rebalance the global trading system in favor of the United States as part of his “America First” policy.