WASHINGTON — Japan has started deploying land-based Patriot interceptors after North Korea threatened to send ballistic missiles flying over western Japan and landing near Guam.

The Japanese Defense Ministry said Friday the Patriot Advanced Capability-3, or PAC-3, surface-to-air interceptors are being deployed at four locations: Hiroshima, Kochi, Shimane and Ehime.

The deployment is largely aimed at responding to the risk of falling fragments while missiles fly over the region.

The four PAC-3 systems are brought from eastern Japan, as its missile defense is largely centered around Tokyo. They are expected to arrive in the designated sites early Saturday.

The ministry did not confirm whether Defense Minister Itsunori Onodera has already issued an order to shoot down incoming missiles.

Meanwhile, American and South Korean officials said they would move forward with large-scale military exercises later this month that North Korea claims are a rehearsal for war.

An escalating exchange of provocative rhetoric between the United States and North Korea is alarming international leaders. Russia’s foreign minister, Sergey Lavrov, estimated the risk of a military conflict between the U.S. and North Korea as “very high,” and said Moscow is deeply concerned.

German Chancellor Angela Merkel declined to say whether Germany would stand with the U.S. in case of a military conflict with North Korea. She called on the U.N. Security Council to continue to address the issue.

U.S. President Donald Trump said this week the U.S. would unleash “fire and fury” on North Korea if it continued to threaten the country.