The U.S. government has approved the sale of anti-ballistic missiles to Japan to defend itself against a growing nuclear and missile threat from North Korea, a State Department official said Tuesday.

News of the sale comes as North and South Korea hold their first talks in more than two years aimed at solving the crisis over the North's nuclear missile program.

The missile deal follows a year of ramped-up North Korean missile launches, some of them over Japanese territory, and its sixth and most powerful nuclear test. These actions have prompted a ramped-up U.S.-led campaign to toughen U.N. sanctions, which Pyongyang has called an act of war.

The State Department on Tuesday asked Congress to approve the $133 million sale of the four missiles and related hardware, which can be launched from destroyers at sea or from a land-based system.

The sale of the anti-ballistic missiles, made by Raytheon Co. and BAE Systems, follows through "on President Trump's commitment to provide additional defensive capabilities to treaty allies threatened by the DPRK's provocative behavior," the official said, using the initials for North Korea's formal name, the Democratic People's Republic of Korea.

Japan formally decided in December it would expand its ballistic missile defense system with U.S.-made ground-based Aegis radar stations and interceptors.

The proposal to build two Aegis Ashore batteries without the missiles will likely cost at least $2 billion and was not likely to be operational until 2023 at the earliest, sources familiar with the plan said in December.

Defense Minister Itsunori Onodera and U.S. Secretary of Defense Jim Mattis, in a phone call on Monday, "condemned North Korea's reckless and unlawful behavior," according to a Pentagon statement.