Taiwanese President Tsai Ing-wen said the United States plans to “cooperate” between the US National Guard and the Taiwanese military as it strengthens security ties in the face of a growing threat from China from the Taipei government.

During a meeting with US Senator Tammy Duckworth in her office in Taipei, Tsai noted that Duckworth is a major sponsor of the Taiwan Partnership Act, which has received bipartisan support in the US Congress, although it has not yet become law.

“As a result, the US Department of Defense is currently actively planning cooperation between the US National Guard and the Taiwan Defense Forces,” Tsai said. No details were given.

“We look forward to closer and deeper cooperation between Taiwan and the United States on regional security issues,” Tsai added.

Duckworth said she made the visit to reaffirm her country’s support for Taiwan and that US lawmakers have “tremendous” support for the island.

“We hope that Taiwan and the United States will take new steps together in the near future to develop concrete plans to deepen our economic partnership,” Tsai said.

The United States is Taiwan’s most important supporter and supplier of weapons, although it does not have official diplomatic relations. China is stepping up its military operations near Taiwan to assert its claim to sovereignty over the island.

Last week, the Chinese military said it recently conducted drills around Taiwan as a “strong warning” against “collusion” with the US.

This came after US President Joe Biden angered China when he appeared to indicate a change in US “strategic ambiguity” policy on Taiwan, saying his country would intervene militarily if China attacked the island. US officials said no change in policy had taken place.

Taiwanese media have previously reported that Taiwan may partner with the Hawaiian National Guard in this program.