Amid heightened tensions in the Persian Gulf, Chief Cabinet Secretary Yoshihide Suga on Friday hinted that Self-Defense Forces troops could be dispatched to waters in the region to help protect shipping.

“We’ll make a judgement in a comprehensive manner after consideration from various perspectives,” Suga told reporters.

He said factors include the necessity of stable crude oil supplies and Tokyo’s balancing act in maintaining relations with both Tehran and Washington.

Suga made the remark when asked about how Japan may respond to a U.S. request for a maritime coalition to protect commercial shipping in waters off Iran, including in the tight Strait of Hormuz.

He declined to answer directly, but stressed that the government is currently discussing how to safeguard ships in the region if they have links to Japan or Japanese trade.

Suga’s comments came a day after government sources said that Japan may send vessels to patrol off Yemen rather than join a U.S.-led coalition aimed at protecting shipping in the Strait of Hormuz.

The administration of Prime Minister Shinzo Abe is reluctant to send the Maritime Self-Defense Force to the strait, a key sea lane through which around one-fifth of the world’s oil passes, out of concern that doing so could hurt Tokyo’s friendly ties with Tehran.

But it is under mounting pressure from Washington to participate in the U.S. effort, dubbed Operation Sentinel, with Pentagon chief Mark Esper earlier this week urging Japan to “strongly consider” it.

As a compromise, Japan is considering sending MSDF destroyers and P-3C Orion surveillance planes to the Bab el-Mandeb Strait between Yemen and the Horn of Africa, the sources said.

“We can’t just do nothing,” a senior Abe administration official said.

The mission would likely be taken up by forces already engaged in anti-piracy operations off Somalia. The Japanese vessels would not be part of the U.S.-led coalition, though the area of operations would overlap.

Abe hopes to discuss the issue with U.S. President Donald Trump when they meet later this month in France on the sidelines of the Group of Seven summit, according to the sources, with a final decision dependent on how other U.S. allies opt to proceed.

Britain and Israel have announced they will participate in the coalition, but Germany has declined.

The U.S. is planning the move after Iran was allegedly behind a number of incidents involving foreign-registered vessels transiting through the vital waterway.

Officials in the Abe administration think such a mission would be possible under existing legislation.

Activities overseas involving the Self-Defense Forces are restricted under the war-renouncing Constitution.