WASHINGTON/BEIJING, April 27 -- The U.S. warning of "other options" against Pyongyang concerning its nuclear and missile programs will further deepen animosity between the two countries and have a negative impact on the Korean Peninsula situation, observers believe.

U.S. State Department spokesman Mark Toner on Tuesday warned that Washington will "look at other options" if the Democratic People's Republic of Korea (DPRK) continues its nuclear and ballistic missile tests.

However, he did not specify what options the United States is considering.

Given the long-standing hostility and distrust between Washington and Pyongyang, tougher U.S. stance will not ease tension on the Korean Peninsula, but create a vicious circle on the issue.

Ling Shengli, secretary-general of the International Security Studies Center at the China Foreign Affairs University, emphasized that compared with sanctions and isolation, engaging Pyongyang and encouraging economic reform could lead the country to abandoning its nuclear weapons.

A great many observers and analysts, among them Jin Canrong, vice president of the School of International Studies at Renmin University, have also noted that any progress toward denuclearization on the Korean Peninsula hinges on improvement in ties between Washington and Pyongyang.

However, in a CBS interview aired Tuesday, U.S. President Barack Obama remained tough, describing the country "a massive challenge."

He defended a plan to deploy the Terminal High Altitude Area Defense missile system on the Korean Peninsula, saying that "so that even as we try to resolve the underlying problem of nuclear development inside of North Korea, we're also setting up a shield that can at least block the relatively low-level threats that they're posing right now."

China and Russia are opposed to the possible deployment of the missile system, which they believe will create a real threat to their security and the stability in Northeast Asia.

White House spokesman Josh Earnest said Tuesday that the international sanctions on the DPRK have not made a desired change in Pyongyang's behavior. "But what we have succeeded in doing is working with the international community to ramp up the pressure on the North Korean government even further."

His words can be indirect evidence of the failure of tit-for-tat retaliation, which will only lead to a lose-lose situation.

It is worth noting that the thorny Iranian nuclear issue has made progress through diplomacy, so the international community should also give the Korean Peninsula conundrum a chance at the negotiating table.

Pyongyang on Sunday announced the test-firing of a submarine-launched ballistic missile. South Korea's military said the missile was fired on Saturday in waters off the DPRK's northeast coast and flew about 30 km.

It is believed that the DPRK might conduct another test before a national congress of the ruling Workers' Party of Korea scheduled for May 6.

The party congress will be the first major conference in 36 years and the first under the current top leader Kim Jong Un.