That the missile landed within 200 nautical miles of the Japanese coast was an "extremely problematic act for the safety of airplanes and ships" Japan's Chief Cabinet Secretary Yoshihide Suga said in a statement. The launch, read the statement, "is clearly violating the UN resolution. The repeated provocative acts by North Korea is absolutely not acceptable."

The Japanese Prime Minister said a "firm protest" was lodged with North Korea and that Tokyo would take action "together with the United States." Analysts say Japan's options for dealing with North Korea unilaterally are limited.

Tokyo couldn't carry out a military response alone, said Carl Schuster, a Hawaii Pacific University professor and former director of operations at the US Pacific Command's Joint Intelligence Center.

"Japan lacks the ballistic missiles, intelligence, targeting and reconnaissance assets, or electronic warfare and air defense suppression capability required to carry out any effective military response," Schuster said.

However, Japan could do some things that might hurt North Korea economically, he said, such as stopping and searching North Korean merchant and fishing vessels in Japanese waters.

The government of South Korean President Moon Jae-in, who took office in early May and who has advocated dialogue with the North, condemned Monday's launch.

"It is a severe threat to the peace and stability of not only the Korean Peninsula, but also the international community," said a statement from South Korea's Ministry of Foreign Affairs. "Since our new government took office, North Korea has been frequently and repeatedly conducting provocation in such manner. This is in direct opposition to our demands in regards to the denuclearization and peace of the Korean Peninsula."

"North Korea's continuous provocative actions will cause its own isolation and it will be facing strong punishment from our military, South Korea and US alliance and the international community," a statement from South Korea's Joint Chiefs said.

Despite that rhetoric, the allies have not given North Korea any "red lines" which it cannot cross or face a military strike, said Adam Mount, senior fellow at the Center for American Progress.

"If they're not clear on what they are attempting to deter, they're not going to have the effect they desire," Mount said.

Even if a military response was considered, the repercussions could be catastrophic.

"If this goes to a military solution, it is going to be tragic on an unbelievable scale," US Defense Secretary James Mattis said earlier this month.

Any pre-emptive military strike on North Korea would put South Korean and Japanese civilian populations, as well as US military installations within those countries, at risk for a North Korean counterstrike. Some estimates put 25 million civilians at risk in the Seoul metropolitan area alone.

Current economic sanctions imposed by the United Nations and others seem to have done nothing to slow North Korea's missile program.

On May 14, North Korea fired what analysts called its most successful test ever in its quest to develop ballistic missiles that can carry nuclear warheads.

That test reached an altitude of more than 2,100 kilometers (1,300 miles), according to North Korea. Analysts said that test gave North Korea critical information on developing a re-entry vehicle for nuclear warheads and showed Pyongyang had a missile capable of striking the US territory of Guam.

On May 21, Pyongyang sent a medium-range ballistic missile into the waters off its east coast. North Korea said that projectile was a ground-to-ground strategic ballistic missile Pukguksong-2, state news agency KCNA reported.

As with a number of previous North Korean tests, the timing of Monday's launch came close to a key international event.

Less than two days earlier, Japan's Prime Minister met with US President Donald Trump and five other leaders from some of the world's most powerful countries at the G7 summit in Italy.

In their final communiqué, Abe and Trump -- along with the leaders of Canada, France, Germany, Italy and the United Kingdom -- said North Korea "increasingly poses new levels of threat of a grave nature to international peace and stability ... through its repeated and ongoing breaches of international law."

North Korea's May 14 test came as China was hosting a major economic summit in Beijing. In early April, Pyongyang tested a missile as Trump and Chinese President Xi Jinping prepared to meet at a summit in Florida.

In a statement, China's Ministry of Foreign Affairs said Beijing urged North Korea to "refrain from any action contrary to UN Security Council resolutions."

Echoing language used in the past, the statement added the situation on the Korean peninsula "is complex and sensitive."

"We hope all parties remain calm and exercise restraint ... and put the peninsula back on the track of peaceful talks," it said.

North Korea has said its missile testing is in reaction to threats against it by the South, the United States and Japan.