HRW's call came shortly before the UN General Assembly adopted a nonbinding resolution that condemns Israel's use of excessive force and calls for measures to protect Palestinians in Gaza. The Israeli authorities said that human rights laws do not apply to ongoing Palestinian protests along the Gaza Strip's eastern border.
Before the vote, the USA ambassador Nikki Haley said there were "no flawless actors" on either side of the Israeli-Palestinian conflict.
The General Assembly adopted a resolution with 120 votes in favour, eight against and 45 abstentions.
In a letter sent to fellow ambassadors, Haley said the United States had presented an amendment to the draft resolution that condemns Hamas for firing rockets at Israel and "inciting violence" along the border with Gaza.
"Rather than improve the lives of the people of Gaza", he said, "Hamas is using the civilian Palestinian population as human shields in its unremitting terror war against Israel".
"Instead, today the General Assembly is devoting its valuable time to the situation in Gaza", Haley said.
"I wish everyone supporting this one-sided resolution would put as much energy into encouraging President Abbas to the negotiating table", she said.
The resolution also calls on all sides to respect worldwide law and condemns all acts of violence against civilians.
Israel's U.N. Ambassador Danny Danon issued a statement welcoming the USA amendment. "Therefore we need a fundamental change in the rules of the game as well as the players".
The draft adopted carries no legal weight but has the moral backing of the majority of United Nations member states.
The General Assembly resolution expresses strong political will of the worldwide community, though, unlike a Security Council resolution, it is not legally binding.
The Palestinians and their supporters chose to go to the 193-member assembly, where there are no vetoes, after the USA vetoed virtually the same resolution in the Security Council on June 1.
The draft resolution being considered Wednesday was proposed by Arab and Islamic countries.
Australia, the Marshall Islands, Micronesia, Nauru, the Solomon Islands and Togo joined the United States and Israel in voting against the resolution. The United States sought to challenge the ruling requiring a two-thirds majority for approval but that was defeated in a separate vote.
The marchers in Gaza have pressed demands for a "right of return" for descendants of Palestinian refugees to ancestral homes in what is now Israel. That vote was 128 to 9, with 35 abstentions. "As part of Hamas's propaganda operation, hundreds of Gazans were injured last week and several dozen died, most of whom were Hamas operatives", the IDF spokesperson Brigadier General Ronen Manelis said back in May.
The United Nations members will condemn the Israel's violent acts in Gaza.
The General Assembly asked UN Secretary Genereal Antonio Guterres to recommend an "international protection mechanism" for occupied Palestinian territory.